So now I’m really pleased to welcome valer melot is really a privilege and a pleasure to welcome you today for this opening conference you are research director at the French alternative energies and atomic energy commission SE at Pierre Simon la plas Institute at parisle University your research team is
Interested in the study of climate and the hydrological Cycles through the analysis of stable isotopes of water and air molecules this involves understanding past and current climate variability to better characterize the coupling between climate and the atmospheric water cycle you have served on numerous National and international projects including the intergovernmental panel on
Climate change and you are associated with the noble Peace Prize 2007 awarded to algar and the ipcc from 2015 to 2023 you have been elected co-chair of the working group one the physical science basis of the ipcc which contributes of all understanding of how the climate system
Works and how it is changing in response to human activity you have published major publication including several books books for the general public as well as children books and you receive a number of prizes and medals for your intensive scientific work so we’re really pleased to welcome you uh come by
And uh the floor is yours and you’re going to give a conference on climate change and transformation challenges than you very much thank you very much for this invitation to come here and share um the state of knowledge regarding this transformation challenges it’s a pleasure to be here in
Rans and it’s also a pleasure to see numerous colleagues as well as young bright minds and we need you to tackle these challenges this is one of the figures from the last ipcc report released last year the synthesis report you can see one year one stripe and an
Indicator of the state of climate changes in global surface temperature so we reaching a level of warming during the last decade of 1.2 de C now at an intensifying Pace compared to the pre-industrial period and why do I speak about transformational challenges you can see the outcomes of future climate assessment ments in
Response to five very contrasted scenarios very high or high greenhouse gas emissions in the future the intermediate scenario Which is closest to public policies in place now in the world and in the case with much more effective climate action to reduce greenhouse gas emissions fast of very
Fast in any case global warming will continue until Global carbon dioxide emissions reach zero net First Transformation build on scientific knowledge to anticipate future changes in climate prepare for for it manage risks and Implement adaptation responses in each region in each sector Second Challenge and will see that some of the
Risks will be very hard to manage there will be limits to ad adapation for ecosystems we depend on for water for biomass for critical aspects including health so the second transformation challenge is to reduce emissions as fast as possible I’ll show that there are options available to do it but there’s
Also a huge need for research development Innovation so as to be prepared to decarbonize hard to Abate sectors and we have added people of different ages we could also add other forms of lives cor Reaves trees long living mammals because what matters are the living conditions for us the old
Ages of those from my age all the conditions for the youngest ones during the coming decades and centuries so just a word about the scientific BAS is for this presentation it is grounded in ipcc report Three Special reports released in 2018 2019 three main reports released in 2021
2022 a special report 500 pages a main working group report 3,000 Pages there are 100 page summaries and 20page summary for policy makers these reports are grounded in the assessment of evidence from scientific technical socioeconomic Publications each chapter is reviewed several times and the summary for policy makers is part of a co-production
Process at the beginning we listen to the needs expressed by all governments they are part of the process they nominate scientists to read to review the reports and at the end they scrutinize word by word the summary for policy makers there’s no equivalent in terms of a scientific peer review
Process at depth so that the assessments are transparent rigorous the conclusions reflect in a balanced way and clearly what is underlying this and this approval process makes this report a scientific basis recognized by all parties so it allows to separate the scientific evidence from climate negotiations that can be grounded on this common
Basis if you don’t like to read long report there’s a French company that has developed an artificial intelligence tool in the spirit of chat GPT so that you can navigate across the reports and you can formulate a plan language question and see where uh the the various parts of the reports related to
Your question and I think this is powerful for you to be able to navigate in the reports for the topics you are interested in I’m also part of the National Climate Change committee which is different ipcc looks at the global picture does not look at the policy of a
Given country does not make any recommendation it has to be neutral so for all possible solutions it looks at the potential limits costs co- benefits or tradeoffs but it does not make any recommendation and this can be frustrating to be honest So within the National Climate Change committee it’s
Different we look at French climate ambition we look at the targets we look at the implementation of climate policies what works what does not work and we develop recommendations and I think for for me it reflects what is expected from scientists not just new knowledge knowledge that is relevant to
Inform decision making a role of trigger of climate policies and sometimes in challenging context a role of Watch Dogs so that the preservation of a healthy planet is implemented and supported by climate policies so let’s dive into where we are now in terms of the state of climate
I’ll focus on the global picture with a few highlights for France so we are in a context where climate action is gaining momentum in France as in around 20 countries greenhouse gas emissions are decreasing including consideration of imports we see that more than half of greenhouse gas emissions are in the
Scope of public policies which have prevented the emission of several billions of tons of greenhouse gases in particular through policies of technological innovation and efficiency it’s also the case for public policies targeting deforestation we also have progresses in adaptation strategies and planning but often reactive you are hit by a heat
Wave you prepare for the same type of Heatwave you hit by a drought you prepare for the same time of drought but it’s not enough transformative it does not prepare you for the new unprecedented events that will occur in the coming decades in a warmer world and there are insufficient Financial flows
So the pace and scale of what has been achieved so far globally is not sufficient to limit the escalation of climate related risks this is Illustrated here when we look at Global greenhouse gas emissions they are exess in the equivalent of carbon dioxide over 100 years this is the metrics used here
You can see that Global greenhouse gas emissions are dominated by carbon dioxide 90% of that due to fossil fuels coal oil and fossil gas you can also see that 10% of CO2 emissions are driven by land use changes in particular deforestation destruction of pit lands and um for other greenhouse gases the
Second most important one is methane a third of it due to leaks from fossil fuels a large part of it due to agricultural practices in particular livestock and meat consumption so what you also see is the increase in global greenhouse gas emissions but for CO2 at a slower Pace
In the last 10 years you have the effect of the covid-19 pandemic and the rebound however the latest estimate for 2023 still shows a global increase in CO2 emissions from fossil fuels we are not yet at a stage where we have managed to reach a peak and a clear de Decline
And that illustrates also the urgency so what is the out what is driving this unsustainable able use of nonrenewable resources fossil energy and sustainable use of land Lifestyles patterns of consumption and production that are not sustainable across regions between countries so there’s of course a larger responsibility of those who have
Industrialized first and now emissions are being uh uh increasing by large emergent economies there are huge con contrast between per capita emissions between countries they are very small today in India or Africa per capita and finally there are huge contrasts between individuals 10% of people in the world account for 40% of
Emissions while half of the world’s population only accounts for 15% of greenhouse gas emissions and this half of the world’s population often lives in very vulnerable context this illustrates challenges of climate Justice and Equity so we add greenhouse gases their levels are increasing in the atmosphere today’s level of CO2 is unprecedented in
More than three million years the level of methane is a uh 2.5 the preindustrial level this is a completely unprecedented in terms of magnitude of the rise of concentration and speed this traps energy which cannot es Escape to Space and the climate system is reacting to this perturbation with amplifying
Factors warmer atmosphere more water vapor in the atmosphere more greenhouse effect from the water vapor a warming effect from clouds the loss of snow and ice losing the um mirror effect amplifying surface warming so where does the excess heat go the excess heat trapped in the climate system 1% warms
The atmosphere 5% warms the soils of course it affects every form of life over the continents the growing season lengths for instance 3% is converted into the Melt of snow and Ice 1 kilogram of CO2 15 kilogram of Glacier Ice to be lost one degree of global warming one
Meter one month less of snowfall it mean elevation in the Alps these are two direct illustrations so a widespread loss of glaciers the melting of Greenland has increased the fast flow of some Antarctic sectors has accelerated and so ice stored on the continents reaches the ocean and contributes to sea level rise
Most of the excess heat goes into the ocean 90% it makes the ocean expand the rate of sea level rise is accelerating as a direct consequence of the perturbation of the earth energy balance and there are irreversible aspects the time span for mixing of the ocean waters is
Several hundreds of years the ocean is picking up heat carbon leading to to its acidification deep otion changes sea level rise they will be irreversible on hundreds 2 thousands of years and that’s what we are triggering now so if we look at global warming the figure I showed previously with the
Stripes this is the assessments that we had in 2021 and you can see that the Red Bar show observed warming the second red bar show what is due to human activities and you can see that it is equal to observed warming the effect of greenhouse gases
The first gray bar is larger than what is observed because it’s partly masked by the cooling effect of pollution particles and in the last 20 years due to air quality improvement policies in Europe North America and China they have been targeted policies to remove the emission of these particles of course
That’s beneficial for public health but we have lost the cooling effect of the pollution particles it adds to the warming effect of greenhouse gases now these two factors go in the same direction so we have implemented a process from scientists who have developed the ipcc assessments to
Provide an annual update to the state of global CL climate so the the first one was released in June 2023 you have the list to the publication what does it show two years from the last physical science basis assessment an increase in greenhouse gas emissions an increase in concentrations in the atmosphere more
Heat trapping effect more warming due to human influence what also I would like to highlight is the state of global climate updated and until the end of 2023 you can see record warming at the global scale we are close for the first time to reach 1.5° C above pre
Industrial it has occurred at the scale of a few months it’s the first time it’s occurring at the scale of 12 years and the more you add greenhouse gases the more frequent it will be when it’s one year out of two expected by 2030 it means we’ve reached that level of
Warming not just for one year but in the climate sense averaged over 20 years and a surprise recently was the loss of Antarctic sea ice you can see that until 2015 there were large fluctuations a small increasing Trend but now we see years with extreme loss of Antarctic sea
Ice it could be caused by the uptake of heat by the ocean around Antarctica preven tempting sea eyes to form in the case of storms that dislocate it and so maybe a new state encountered in this region it illustrates that what happens over the continent affects the whole
Planet and if we want to preserve pristine ecosystems around the Antarctic we need to limit the magnitude of warming warming affects mean climate everywhere it also affects extreme events a direct consequence of a warmer climate is a reduced frequency and intensity of cold extremes and an increase in the occurence and intensity
Of hot extremes one hexagon is a world region we are here in Western Central Europe south of France is in the Mediterranean region and every region in red is where we observe this intensification of hot extremes the number of dots indicates the confidence in the attribution of the likelihood of
Occurrence and intensity to human caused climate change it’s widespread in 2019 in France more than 45 degrees in the south of France this type of event would have been extremely unlikely in a pre-industrial climate for rainfall it is a direct effect of a warmer atmosphere which can
Hold 7% more moisture per degree of warming do the same storm today can lead to much larger amounts of rainfall compared to a few decades ago this is already observed in the south of France it starts to be observed for thunderstorm events in these latitudes an increase in the record intensity of
Thunderstorms and our infrastructures you know water uh water systems are not designed for these extreme rainfall events we have also artificialized a lot of soils through urbanization or agricultural practices so both local features and climate change combine to increase flush flood risks in many regions and finally a warmer atmosphere leads to more
Evaporation more transpiration an increase in what we call the atmospheric demand therefore it transforms a normal period of reduced rainfall in a more severe drought so the regions that appear in yellow are regions where we see an increase in the frequency and intensity of these agricultural droughts that affect soil
Moisture drought and rain and and heat combine to increase water um and heat stress on plants animals they can combine to increase the occurrence of fire weather conditions that can lead to more extreme wild fires this is observed at the very large scale and is also a result of
Warming coming back to impacts and risks they’re not just the outcomes of these hazards and these climatic impact drivers they are the result of their interactions with exposure vulnerability and the responses that we can Implement to limit impacts and risks this is uh what I presented
Previously um uh without uh uh the data these are emissions per person in more than 180 Nations you can see in some places of the world like Qatar or oops or Emirates oh like here emissions that can be more than 20 and up to 40 tons of
CO2 per person and per year in North America Australia more than 15 Tons per person and per year in Europe it’s usually around 5 to 10 depending on the Energy Mix however half of the world’s population has emitted almost nothing in the past and today and lives in count
Countries with very high vulnerability index to a warming climate and that’s the illustration of climate Justice where you have those most responsible and those most vulnerable who need to discuss together on what is the best strategy to tackle a changing climate in this most vulnerable context there’s a
Need for basic access to public services water energy Education Health so the challenge is to find affordable solutions that can make low carbon Solutions available for those who have the most urgent need to access these basic services for development and for the quality of life if you are interested to follow up
What is the diagnosis we can have on high impact events I give you two sides here one is the world weather attribution project it’s a group of scientists that looks at high impact events and answer the question is it just a rare natural event part of climate variability can we see the
Fingerprint of human cause climate change how do our models represent what is observed and how much will these events that have already high impacts will continue to recur and intensify in the future and you can see examples of recent outcomes for instance a footprint of human cause climate change on
Wildfire in Canada last summer leading to the emissions of 500 Megaton of carbon due to the loss of carbon stored in Canadian forests this illustrates some of the feedbacks that can be triggered in a warmer world if the biomass storing carbon is lost and that carbon goes back to the atmosphere today
The vegetation and soils absorb about a third of our CO2 emissions the ocean about 25% this is a giant service provided by ecosystem picking up about half of our emissions but in a warmer world the efficiency of these sinks will be challenged by a warmer ocean mixing less
Well and by the effect of heat water fire stress on vegetation and soils so what we see now is uh the increase of widespread impacts and losses and damages attributed to human caused climate change and you know we are living in Europe in a agricultural crisis food production is at the
Forefront of climate impact they affect physical renewable water availability Crop Production for agriculture and livestock they affect the production of aquaculture and Fisheries the the fish catch potential in the tropics has reduced due to a warmer ocean there are multiple effects for health in particular excess mortality associated with heat waves but
Also mental health due to displacements in particular people affected by floods and affected by wild fires that have to move from their homes are affected by mental health trauma that can persist for months for cities the largest impacts are associated with the flood risks in France we are particular
Because we have 10,000 houses built on arilus soils that are affected by swelling and shrinking in the case of droughts so we are particularly exposed to building drought risks with increased Insurance costs and half of the studied speeches are moving just to try to keep their habitats we see Mass mortality of
Spees over land and in the ocean Tre mortality in France has strongly increased just in the last 10 years and the ability of the growth of forest to store carbon in France was around 7% of our emissions one decade ago it has decreased to only 4% now so it
Illustrates the loss of services from these ecosystems including carbon storage I’ve added a few pictograms just to give highlights the the habitat suitability for some vectors of diseases such as ticks mosquitoes or mides is expanding today life livestock farming in France is affected by a new disease epizoic hemorragic fever transmitted by
Mides biting mides it is shown that the habitat suitable for this mid is reaching Europe due to warmer conditions and milder winter in particular um the mosquito is to illustrate the increased risk for dingy fever we see now a widespread outbreak in the Tropics of Deni fever the vector bone disease is
Now installed almost everywhere in France tiger mosquito and we have now autonomous cases with an increased risk and an additional pressure on the health system due to these effects so just to remember these impacts they are caused by changes in physical climate conditions attributed to human influence
On climate and they will increase with every increment of future warming as students what can you do you can learn how to access to this information climate data climate projections to learn to use the 33 climatic impact drivers that have been identified and do stress tests for
Future projects so that for a city for an industry for for an Agricultural activity you are able to provide a climate service that allows to better prepare manage risks and adapt just coming back to France we strongly exposed to climate change including for food production and not
Ready this was Illustrated in 2022 with a cost for insurance companies of 3 billion EUR and this are only the insured costs 2022 three major Heat waves uh major wildfires including lots of wetland speeches Marine heat waves um and multiple consequences of drought including shortage of drinking water provided to several
Municipalities 2023 has been the second hot hottest day uh so you can see in France for 1.2 degrees globally we are already at 2 degrees for the last decade these record years are reaching 3° above preindustrial so we are entering into new territory um we had again an exceptional
Heat Wave last summer with excess mortality of more than 5,000 people the hottest fall on record well today is a record actually in February and we had record monthly precipitation including major floods and impacts in northern France together with severe drought in the South and in oversea territories record heat and historical drought
Including affecting dramatically Water Resources in the island of mayot thinking of losses and damages there has been an advance recently at cop 28 with a new Fund in the spirit of climate Justice to help those most vulnerable most affected to recover and rebuild after disasters just to give you a hint of
Where we are in in terms of challenges countries have given pledges to contribute to that fund France is playing good about $1 million on the table us first historical emitter largest one of the largest emissions per capita exports of fossil fuels they have only placed on the table $17 million it’s honestly
Ridiculous uh and it illustrates how much those responsible for emissions are extremely Rel reluctant to be accountable for the loss and damages that they cause profits of fossil fuel companies they don’t contribute at all to the loss and damage cost this illustrates some of the challenges that
We see and to give you a sense what is on the table is around 0.7 billion doar on this new fund the costs to address losses and damages they are expected to be between 100 and 400 billion what has been put on the table is only equal to
The salaries of the three most wellp paid football players in the world are we serious so let’s look at the possible Futures and the possible Futures they depend on us the geophysical knowledge has advanced the climate response constrained by what we know from past climates feedback loops observational
Constraints it has allowed to reduce the uncertainty on this climate response by a factor of two but we need to continue to advance that this is only shown by 2050 because if warming is really large more than two degrees after 2050 then we enter more uncertainty about the carbon cycle feedbacks that
Could increase the uncertainty on this relationship however this is a a very solid geophysical constraint showing the Clos link between cumulative CO2 emissions and warming in Black you have what has already been observed and then you have projections for different future scenarios what does it say it says every
Ton of CO2 we add contributes to Future warming what we all also know is that if we would put our CO2 emissions to zero okay now or through transformations to be implemented there would be no more warming there’s an uncertainty by a few tens of degrees including on the
Sign so the second thing is we need to reach Net Zero CO2 emissions if we want to limit future global warming and when we reach that we expect warming to stabilize that will be the dominant effect and the dominant player for future warming of course we also need to limit
The net effect of other grp greenhouse gases and particles but if we don’t act of Co on co2 we won’t stabilize future warming that’s the key thing so it’s the same graph as the stripes at the beginning but it illustrates the scenarios of Emissions on the left side panel very high high
Intermediate low and very low emissions and then it illustrates the temperature response at the global scale so maybe the posi thing is the following if we strongly reduce emissions at the global scale we would see the benefits within 20 years of global warming stabilization the second thing is
Reality won’t look like these boring curves what is shown here is the average of all climate models constrained by uh our assessed climate response in reality you’ll have volcanic eruptions you’ll have natural variability that will modulate these Trends a few years ago they played in the opposite direction as human caused warming with
The appearance of a slow down warming had continued but for surface temperature it showed a slow down and some people jumped on it warming has stopped no need to worry at the moment it’s playing in the same direction so we see very fast warming extreme year 2023
Because we have an on top of human CA warming some people think it’s out of control we can’t do anything anymore so it also requires to be able to discern the gradual human CA warming effect from these modulations by natural variability and not over interpret single years I’m a paleoclimatologist it’s
Always useful to place current changes in a broader context so here you have 60 million years the past thousand million years and the last 2,000 years what you can see in the upper panel are changes in atmospheric CO2 concentration and you can see how fast
We’ve been out of the range of the last million years recreating an atmosphere that was previously similar 3 to 14 million years ago on the lower panel you can see estimates of past changes in global surface temperature warming observed to date now we are out of the range of the current
Interglacial period when we look at the last decade and future warming projections limiting warming close to 1.5 degrees it means staying in the range of the warming of the last interglacial periods more than that it’s unknown territory it’s unknown territory for many ecosystems not just because of
The mean warming but also the pace which is tens to hundreds of times faster than those of the past in particular in the tropics what can we learn from the past there are still a lot of things to learn acclimatation of speeches and ecosystems organisms but also limits to adaptation
Capacities and we do not fully take use of what we can learn from the past what does every increment of warming mean the more you have warming at the global scale the more you have warming everywhere with a larger warming Overland and very large around the North
Pole when you increase the warming level you intensifies the water cycle with contrasted effects in annual mean a tendency to have more rainfall in cold regions cold seasons and a tendency to have less rainfall in regions with a Mediterranean climate including South Africa the Amazon region Central America
Or around the Mediterranean Sea so you can access these informations in our interactive Atlas play with themselves yourself what is your variable of interest your region your time Horizon and you can access to this information in an interactive way but what does it mean for extreme events the upper panel is not mean
Temperature it’s the temperature of the hottest day in increases more than the mean disproportionately events that were very rare in the past are becoming more and more frequent and that’s a direct consequence of forming and you can see the area where the increase is strongest is around the
Mediterranean Sea if we look at the last 20 years the increase in hot Extremes in Western Europe is even twice larger than in our models do we get it right do we correctly anticipate changes in atmospheric circulation patterns block in that increase heat waves these are open scientific questions a warmer um atmosphere
Includes an intensification of the water cycle and its variability more very wet very dry seasons more very wet very dry events looking at aridification processes these appear in regions in the middle panel in Orange more warmings mean a decrease in soil moisture proportional to the warming it’s the
Case for Western Europe in summer the Mediterranean it’s the case for the Amazon the central ples in the US Central America this is a major challenge for adaptation of ecosystem management and farming practices as well as water use if you look at the lowest panel what you see that even in drying
Regions you will have an increase in the record precipitation in the wetest day of the year so you need to prepare both to increase water scarcity and increased excess rainfall concent concentrated in a few events and this is a major challenge for multiple sectors on how to best prepare for that avoiding
Maladaptation I will give you a couple of examples adaptation that can be successful or mal adaptation air conditioning what do you think if you live if you are old fragile if you live in a dense urban center in a poorly insulated flat can be your solution but you release the
Calories outside you increase Urban heat island effect for those working Outdoors it can make it worse adaptation or maladaptation artificial snowmaking adaptation or mal adaptation you use public money to preserve an activity jobs economical activity in mid latitude uh mid elevation mountains but at the same time you lock in investments into that
Direction and then when it’s not cold enough you can’t make it so adaptation or mal adaptation surface water storage can be an adaptation when you have issues with a very shallow underground water storage so that you can store Winter precipitation use it in summer but who pays for that who
Benefits from that does it affect ecosystem water use and and in rivers and and in Water Systems adaptation or maladaptation and these are complex case studies that you will have to address in many situations so I’ll just go quickly through some of the main risks and first
Risk of a warming climate is the loss of speeches and degradation of ecosystems this is Illustrated here from a modeling study of 30,000 of mammals birds reptiles marine fish Krill and even sea grasses and corals and you can see that it’s just using temperature and looking
At um organisms that would be exposed to potentially harmful conditions if they don’t move if they stay at the same place you can see that the risk is already here now in particular in the tropics for emic speeches cor reefs and it will increase in space and severity
With with every increment of global warming what can be done of course protected areas removing other pressures locally corridors to support um uh the movement of speeches protection restoration of ecosystems that’s critical limiting warming as well and when you look at the severity of risks for different land systems or ocean
Systems you can see that they increase with the level of warming for Wildlife damages permafrost degradation loss of biodiversity or tree mortality and they also increase with warming for multiple types of ocean um ecosystems starting from warm water corals but even at the depths of the sea no Spees is protected
From the consequences of a warming climate and in addition to our duty to preserve protect ecosystems their functions and benefits from their services this this shows hard limits hard limits for us in a warmer world when we lose the snow and the ice in the mountains we lose the ability of
The cryosphere to store water in Winter and provide water in river systems when we mostly need it in summer for irrigation in particular this will affect about two billion people twoth thirds of irrigated areas second example slower growth of forests yields decreased for crops which biomass will be available for us in a
Warmer world and there will be hard limits and today the French energy and climate strategy does not manage to close for the use of biomass and we need also to preserve ecosystems for biodiversity not just use it for us it’s a major challenge is these hard limits so higher warming loss of response
Options for us lot of opportunities so in terms of tackling climate change in terms of limiting risks we need to limit the magnitude of warming there are multiple risks for human health I want to illustrate this one the conditions of heat and humidity that can be harmful for human health it
Means if you have a physical activity Outdoors you put your life at risk it already occurs several days per year in tropical regions and this the number of years and the region exposed will increase with every increment of warming what does it mean you remember the risk for building
Stadiums in Qatar or other places it’s already the case now it’s harmful for building sectors it will be harmful for the um agricultural sector as well if you lose the ability to work Outdoors you can reduce the productivity and you will have economical losses which is also a consequence of this threat
For some speeches um with the current practices it is expected that the yields can increase with temperature and decline one example is mice production that has a peak above 35 degrees and then a decline so regions that appear here in purple are regions where crop yields for mice production without new adaptation
Approaches is expected to decrease will’ll be more people to feed some of the food produced some of the crops are for livestock feeding some are for direct human feeding if we keep the same diets it will be extremely difficult to preserve food Security in a warmer world with a
Larger population and threats for crop yields for core um uh Crop Productions you can see that for fishies the crop yields the catch potential uh is projected to continue to decrease in the Tropics there’s a large uncertainty for the Arctic and Antarctic but we already see increased pressures from Fisheries
To uh move their exploitation areas in the Arctic in the Antarctic also threatening uh marine ecosystems due to increased potential um Capt capture pressures and Source potential sources of conflict as well in these areas I want to highlight the complexity of the risks and they have been experienced
Already for instance in Pakistan and India um for spring conditions associated with extreme heat and drought in this type of situations the the climate uh affects food yield food production food prices on local markets but because people cannot work when it’s so hot they don’t have any income so you
Can see the two factors play in the same direction to threaten the ability to buy food that is needed at the daily scale and when you look at the potential consequences they affect malnutrition and in particular maternal malnutrition and child undernutrition this is a major concern I
Was on a call recently with UNICEF extremely concerned about increased child undernutrition in many regions following extreme hot and dry conditions when you look at this is just one example but when you look at adaptation strategies public policies they are often blind for vulnerabilities that are gender specific or child specific so
Just pay attention to these dimensions for instance old women are extraordinary more exposed to excess mortality due to heat waves so analysis public policies need to include these gender specific aspects or age specific aspects and we’re not there yet I want to end by action and when you
Look at heat related morbidity and mortality of course the threat at the global scale depends on the level of global warming and extreme events that will intensify but it also depends on the scale of adaptation implemented and proactive adapt can be access and quality of Health Systems it can be also quality of
Housing and buildings having Urban Design that creates cooling spaces so that people can have a rest during these extreme heat conditions and you can see proactive adaptation which has a cost can limit the effect of a warming climate in some boundaries regarding food insecurity the type of socioeconomic development plays a key
Role and in a world where you have low population growth you help people get out of extreme poverty uh in a world where uh you have a reasonable uh income for small farmers you protect farming land and you strengthen adaptative capacities of farmers you can limit uh the magnitude of food insecurity risks
And this also calls for a shift in diets Less meat more vegetable proteins as part of that process to limit pressure on land in other cases our own choices can increase the threats for a warmer World by local pressures on how we use Land There are irreversible aspect
Including sea level rise sea level has rised by 20 cm since 1900 it will increase by 20 cm by 2050 by the end of the centy depends first on us and the amount of greenhouse gases in the atmosphere a factor of two 50 cm for very very low emissions
Possibly one meter with very high emissions but it also depends on deep uncertainty and we have deep uncertainty on some ice sheet processes that can cause their instability for sectors of Antarctica what are the needs for large industrial complexes on Coast large cities growing on Coast they don’t want
Only the best confidence information they want information on physically plausible high risks so physically plausible high risks are if these unknown processes are triggered what can be a worst case scenario that is plausible it is illustrated by the dashed line up to 1.5 meters by the end
Of the century and many more meters in the coming ones and this is the type of information that is needed for um risk sensitive infrastructures that project on the long-term sea level is a good example because responding to sea level rise requires long-term planning and you can
Build on ecosystems but if sea level rises fast it doesn’t work anymore you can move sediments sandbags and gravel and so on same thing if SE level rises fast you lose it it was shown during last storms on the western French Coast you can build hard infrastructures
Like in Venice or London it’s very expensive it will be only for wealthy large cities what about the rest and the other options there can be to stop building in exposed areas or to plan the relocation this is a major challenge we only see the first consequences high
Tide chronic flooding extreme sea level rise during storms erosion it’s only the beginning it requires new skills and the ability to uh develop approaches within societies deliberations to develop how to do it what is the will of the local communities to be done so as to anticipate and implement the various responses
Possible in some regions risks are really high in Africa risks are extremely high for food production preservation of ecosystems and biodiversity health and sea level rise already in Africa climate change has reduced economical growth it is the continent most affected if we look at Europe in Europe we have identified four main risks
Extreme heat for people for ecosystems and for Crop Production together with drought and flood risks water scarcity risks are important and it’s not just agricultural drought it’s also you know the r level so low you block the industrial activity in the whole area and it affects something like
1% of the G German National growth same thing in North Italy with a poor River so low that it stops the economic activity at the very large scale and large set of risks associated with flooding we’ve built all our cities along rivers and on the coast historically
So the amount of buildings exposed is very large and it calls for anticipation risk management adaptation strategies to be implemented and new skills new jobs new needs for Climate Services to be used in various sectors I’ve mentioned small islands that concern French territories overseas where there’s a a higher
Exposure to water stress because there’s not a possibility to have large water storages on the ground and larger dependency on the health of ecosystems that play a key role in providing um resources through tourism or local fisheries and in some cases there are issues of hability and I think Vol gang
You will address these issues together with solidarity challenges related to losses and damages so maybe the take-home message for France coming back to that same thing Stripes different scenarios but for French temperature the rectangle highlights what has been so far historical record warmth in 2022 if you look in the future by
2050 if global warming reaches two degrees which is likely given current policies it means three degrees in France it means the hottest year will be the mean year so we need to prepare for the hottest year of 2050 2040 2030 the largest impacts were encountered with the heat wave of 2003
Some of you may remember that one large excess mortality two weeks in August in today’s climate this type of extreme atmospheric pattern would lead to four degrees warmer heat so this is an example of information that is needed to prepare for worst case things in every region including in
France you can see that business as usual is not an option and there will be calls for multiple Transformations adaptation but also reducing emissions because if we don’t reduce emissions globally and in every region it will be very difficult to continue to adapt and losses and damages will uh of course
Continue to ramp up so let’s look at France we have reduced our row emissions since the 1990s it’s the green curve 2022 a decrease by 2.7% last year first nine months 4.6% looks great doesn’t it however what are the effects of the energy crisis due to the war in Ukraine
Inflation and unability of people to just buy the usual consumption things what is uh uh how to deconvolve the conjunctural factors from the efficiency of changes that affect the systems we depend on and help them transform if these emissions are just due to being poorer if the reduction is just due to
Being poorer you can expect rebound effects unless you really change the infrastructure the practices the Norms the social values that will lead to longer term reductions and if you look at the difference between raow and net emissions you can see a challenge net emissions are after accounted for managed Forest growth and
As I described previously trees have excess mortality the growth of forest has slowed and you can see that the sink has reduced when we account for that and for the fires in 2022 France might miss its second goal its second carbon budget after missing the first one and revising
The second one downwards it shows how hard it is to reach targets and how we need to not bet too much on ecosystems and their ability to store carbon we also see that in the future for France to keep with its own targets and those from the European Union the
Rate of emission reductions should be increasing from around two to around four five% per year it requires accelerated efforts in each sector supported by just transition economical policies and what do we see now in Europe a back backslash uh the agricultural sector doesn’t want to have an increase in the
Cost for fossil fuels used in the sector the building sector has the same situation so you can see that you need multiple skills to be able to design smart policies um building on the understanding of the disproportionate effects on some sectors and the engagement of all sectors so as to have
A pace that can be supported and with Benefits that can motivate to trigger further action just a note the food system is 22% of the French carbon footprint including half of it from imported emissions one particularity in France is that you can see when we account for trade we import a lot of
Emissions with the equipment and imports that we have so we also depend on Supply chains and it illustrates why it matters that we tackle the climate footprint along these food supply or trade uh chains the national climate change committee had released a report on the French carbon footprint showing the
Potential also for multiple industrial sectors to have a positive effect along the supply chain so that the regulations places placed in Europe affect the production conditions in other regions of the world so coming back to our remaining carbon budgets you can translate every goal for future warming like in the Paris agreement limiting
Warming well below two degrees or close to 1.5 in a remaining carbon budget the one remaining for limiting warming at 1.5 is shrinking really fast it’s now estimated to be 250 billion tons of CO2 six seven years at today’s emissions rates globally what does it
Mean it means if at the global scale CO2 emissions stay at the same level before 2030 we have burned that and therefore we are committed for a warming to exceed that level it also shows that when we look at fossil fuel infrastructures those planned and those already
Operating if we keep them over the initially planned lifetime we will exceed the budget associated with limiting warming well below two degrees translation phasing out coal power plants earlier than planned gas power plants earlier than planned new investments in fossil fuel infrastructures exploitation production is not consistent with the Paris
Agreement and that’s not fully translated in shifts in uh Investments out of the fossil fuel sector towards strategically uh solution oriented sectors so we can look at the pace that is needed if we want to limit warming well below 2° in green we would need to decrease emission by 27% by
2030 and to keep as close as possible to 1.5 by almost a factor of two it’s a huge Challenge and it applies to CO2 as well as methane the two main drivers of warming what we also see and that’s the good news there’s a technical Potential from solutions that are available now
Well-known public policies that have worked to divide emissions by a factor of two playing on three main directions technological innovation practice demand management sufficiency efficiency and ecosystem based responses it’s not one or the other one if you don’t use the whole package it won’t work so in our reports
You can see an assessment of these options I just want to start by showing where we are after cup 28 in dark blue you have implemented policies and what they imply an increase in global emissions by 2030 in light blue you have pledges from all countries if all implemented they could allow a
Tiny decrease 2 to 5% of global emissions in dark blue on the right side of the arrow you have the outcomes of the cup 28 additional decision package in particular for the energy sector for the first time at a meeting of party of the UN convention on climate change
Phasing out fossil fuels has been discussed in a conference hosted by the president of the United Arab Emirates fossil fuel company there’s a description of what has to be done it’s not quantitative they are not precise targets but the main ingredients are there and the most imp important pledge
That was made was to Triple the rate of deployment of renewable energy production and to double the rate of Energy Efficiency progress if this is done and it’s feasible if this is done at the global scale by 2030 we can save emissions of around 4 billion tons CO2 around 10% more we’re
Not there yet it means we will not be on track if it is done only to limit warming at low levels it would Place us in a trajectory that would lead to around 2.5 5 degrees by the end of the century but it’s a non- negligible progress there are sectors that have not
Been addressed in particular the food system it’s really critical because it’s a third of global greenhouse gas emissions what can be done this is the assessment in the ipcc report it’s not a road map it’s not what you have to do in a specific context it’s an assessment at
The global scale system by System energy you have adaptation options for resiliency systems and then you have mitigation options the bar size shows the potential the color scale gives an indication of the costs you can see the huge potential for renewable energy and the small one for carbon capture and
Storage which is promoted by the fossil fuel industry and has been introduced in ipcc reports forced by fossil fuel dependent countries to mention phasing out fossil fuels without abatement a batement means carbon capture and storage on the long term but it’s not taking up at the right pace and the
National Climate Change committee has released a report last November trying to assess what is the true potential for France of using carbon capture and storage for very hard to Abate sectors it will have to be done it will have to be focused on these hard to Abate sectors it needs research and
Development for it to be implementable and it needs Investments with large costs in the land water Food Systems you see a lot of various options including efficiency bioeconomy practices in a way including um the work with ecosystems and um agroecological practices it also highlights the importance of the demand
Side and shifts in diet less an protein Supply more plant-based protein Supply it’s part of the solutions it’s affordable it’s feasible and it can have um health benefits so in green I have tried to highlight what can be the public health impacts of actual climate policies and effective policies you can
Improve air quality you can live longer in a better health with healthier diets you can improve ecosystem health for soils for forests for Agricultural and natural ecosystems looking at other systems such as cities you can see that there are multiple challenges for adaptation and multiple building and transport sector
Mitigation responses there’s no single solution that fits all transport is the first emission sector in France and in France as in other places in the world you have multiple responses public transportations active Mobility walking cycling which requires infrastructure efficient vehicles and electric vehicles so it’s a mix of these strategies that
Has to be designed implemented if you want to efficiently reduce emissions from transport and again you can have multiple benefits for thermal Comfort air quality active mobilities nature in cities and improved Health Systems if it’s welld designed and well implemented and looking at um the industrial sector on the short term it’s
Really the efficiency approaches circular economy approaches that can be implemented now because there’s a large need for research development for hard to Abate sectors to develop the production provision of substitutes to feed stocks fossil fuel energy in these sectors it’s not available now um but it it’s the need now to develop these
Research and development processes so that these Solutions will be affordable in 10 20 years from now and there are multiple solidarity Dimensions that need to be in designed including for instance thinking of what could be a social security for adaptation to a warming climate maybe some of you have followed
The news those affected by the floods in northern France you know displaced no more income struggling to find Solutions limited or covered by insurance companies expanding the social security system to adaptation could be part of an um solidarity response expanding climate change into the way we operate as a solidary
Society I want to say a few things about what we call in French soet sufficiency in English it’s often used to say you need to act in your own lifestyle but in terms of ipcc Assessments it’s really seen as strategies and infrastructures that can enable low carbon Lifestyles make them affordable
It’s the case for our research Community practices how can you transform them to reduce the carbon footprint of students of academic research in Europe the carbon footprint of scientists is around seven tons for the work per year per person for students two tons you know you need University buildings food
Heating I don’t know training sessions and the rest it can be reduced but you need to measure you need to deliberate you need to think of just transition practices and there are multiple initiatives now that also try to develop uh new practices in research in academic to allow lowc carbon professional
Lifestyles as well and generally the approach is in terms of what you avoid and what you avoid can have the largest impact is a long-term plane flight or driving a thermal car how you can shift to a more sustainable transport or diets and then how what you can improve in
Terms for instance of building quality or heating practices and of course they have different requests in terms of investment support but this appro approach of avoid shift improve is quite critical for um sufficiency strategies and I don’t want to dive into this figure which is complex it’s just to say
This is what you need to best develop if you think of climate change you think adaptation reducing emissions nature based Solutions as well each option it has co- benefits and trade-offs and you can look at these Co benefits and tradeoffs using the lens of sustainable development goals do you know what is
The first sustainable development goals from United Nations eradicating extreme poverty that’s the first thing so when you think for instance of I don’t know electric cars and extreme poverty what’s the link well if cars are more expensive to buy it can exacerbate um the difficulty for uh display
Mobility on a daily basis if you make electric cars affordable when you use them on a daily basis they are cheaper so thinking of you know technological innovation poverty helps think differently and think of making Innovation affordable with the spirit of lifting people out of poverty in every
Region of the world and you can see the same for all approaches so when it’s blue it’s when you have a Synergy a co- benefit so climate policies can be Health policies can be poverty reducation policies can be ecosystem biodiversity preservation policies and in Orange you have tradeoffs and so some
Of the most stringent tradeoffs appear with land use increasing pressure on land for biomass for multiple uses can increase pressure on ecosystems and their preservation can challenge food Security in some regions of the world or can challenge land rights for instance for small scale Farmers that don’t have cure
Land rights in developing countries accounting for that is really critical to think of the profile of a response option but also for scientists to assess what has been implemented what can work what can have tradeoffs if you increase the price of oil it will have regressive social
Aspects in particular for those who have old cars uh inefficient heating systems and low income so including that in the design of public policies in economical approaches is critical otherwise people will very well understand the unfairness of the implemented policies and can Rebel of course against that we saw that
With the yellow vest Movement we see not this now with the agricultural crisis in particular due to very difficult um income conditions for many people in the sector so including these social economic Dimension is critical if we want climate policies to be supported and to be successful so basically what we show is
If we don’t limit global warming and act it will be a major threat for a healthy planet and for public health it can cause an increase in inequalities we have a window of opportunity we have solutions that can work that need to be well implemented but we need evidence to inform public
Policies and we need advances the knowledge basis to support Transformations towards Pathways that will allow us to be resilient in a warming climate and Pathways that bring us towards low carbon uh economies as fast as possible so what are specific needs for academic research and young professionals the understanding of how
To build with different forms of knowledge local knowledge and academic knowledge how to co-produce knowledge how to uh strengthen the synergies between climate and other aspirations of societies and how to inform and support behavioral change do you know what is the most stringent obstacle for Effective climate action in Europe in
Europe low perception of risk it’s linked to values belief systems you know lock in from past choices so engaging more broadly with Society um allowing people to enhance their understanding of the causes the consequences but also the solutions is critical every moment of choice every crisis can lock in towards High
Emissions reaching adaptation limits increasing climate risks and ecosystem degradation is that the future you want collectively but every crisis every opportunity of choice is also an opportunity to implement new options for lower emissions systems transitions shift in Social cultural values Norms beliefs lower climate risks better equity and Justice and achievement of
Sustainable development goals so I try to illustrate how much every increment of warming matters you’ve seen that the sense of urgency because if we don’t engage into these Transformations now it will be too slow too late the ability to act so every choice matters and I think
Your choices will matter as well thank [Applause] you thank you very much Valerie for this complete and Global presentation and beautiful presentation too I have to say um I’m sure there’s a lot of question we’re running out of time but it doesn’t matter we’ll take the time to answer the
Questions um so maybe already you have questions in the the first one is always hard to to get okay hello thank you very much for the talk um you mentioned in your presentation that uh you will need both technological Evolution and also ecological response to tackle the issue the problem when you
Discuss with people about global warming they this kind of they form kind of two groups they never agree um so do you have any opinion about that or can we reconcile uh those two approach thank you I I think what matters is uh taking stock also of case studies so as to show
What can be achieved by one strategy or one option but also the limits what can be achieved by the other ones it can be inspiring um not everything is um to be deployed at the same time in the same way in the same context so in some cases
Uh some options Urban centers or industrial activities of course there’s a need for more technology driven responses but in other context like agroecological response they play a critical role for the resilience of for instance food production it has been shown that climate spart smart agriculture for instance has a potential
But also hard limits and agroecological practices are are most suited for deeper transformation than climate resilience on the longer term thank thank you very much for this very informative talk so I have a a question about uh ocean currents what is actually the the current knowledge about the
Impact of climate change and increas in temperature on the ocean currents we all heard recently about a possible collapse of the Gul stream current so is it plausible and and and what will be the consequence about about that thank you very much thank you for the question because I’ve addressed the issue of
Potential tipping points and abrupt change mostly hinting to instability of some Antarctic sectors there are other possibilities for abrupt changes or tipping points uh in Societies in ecosystems locally but also in some aspects of the climate System including what we call the Atlantic meridianal overturning circulation it’s not the
Surface Gulf Stream which is linked to the rotation of the earth it’s really the 3D circulation patterns and and this circulation is driven by density gradients in the ocean so it’s sensitive to density changes with a warmer Ocean or more inflow of fresh water in specific sectors of the ocean so we know
In the past that this circulation has changed abruptly there’s ample evidence from paleoclimatology in particular during cold climates um today uh there are contrasted results from the monitoring systems or from reconstructions they can have been a Slowdown but it’s still debated in particular because a real measurement
You know with a a system uh at depth in the Atlantic Ocean has only be implemented 20 years ago so for 20 years we see like a small drop and a recovery um and then looking at future the issue is do we have the right models are they
Adequate so with very simple models it’s very easy to provoke an Abrupt shift of this circulation and delayed recovery in some cases uh with more complex models it’s more challenging so the paper published last week in one of the science I think science of nature journals is interesting because it’s
Using one of the last pre penultimate generation of climate models not the latest ones and then it does a systematic uh complex system analysis uh in uh uh um without adding greenhouse gasing gases explicitly uh to freshwater inputs it confirms the possibility with a sophisticated climate model to have an Abrupt response to
Freshw changes it does not include the interplay between a warmer world and what would be a collapse of the circulation and the regional consequences um this this has been already assessed with the sensitivity studies in ipcc reports and some of the major changes would be effects on the
Shift in Rain um storm tracks and the rain belts in the tropics that would radically affect water supply in tropical areas in Europe um and then from that study what can we say it does not show completely what would be like the warming levels that could lead to that it Still Remains
Hard to determine it shows it’s plausible but it does not show what would be the conditions under which it would develop it also shows that um there would be limited early warning signs because the question is what can we monitor so that we could be able to
Detect maybe a few years before the start of the occurrence of such a shift apart from the freshwater transport at the tip of South Africa and therefore it calls for a strengthening of the observing system in that region so it’s an illustration of a high-profile publication with a broad communication sometimes poorly
Translated in plain language so I remember because my neighbors told me oh it’s too late we’ve already altered the global ocean currents and Europe will be colder no we’re not there yet and it’s a challenge in terms of allowing everyone to have a proper big picture of where we
We are now what we know what we don’t know but in my view these risks of abrupt changes and irreversible ones um are a strong motivation to act at scale now we don’t want to enter into that territory of course there would be very hard to manage it’s also instrumentalized Now by
Some actors who want to promote very risky approaches such as artificially altering solar radiation geoengineering and it is quite striking for me now that I see private interest using these knowledge and lacks of knowledge about tipping points to promote these types of dangerous responses um hi thank you so much for
Your presentation it was very interesting and also as a French female student I’m very inspired by you so thank you so much um I have so many questions but I’m only going to ask one um what do you think do you truly believe um do you truly believe that
International cooperation can work what do you think about this I think without International cooperation uh it is not possible to have climate action at scale however the current process unfccc DC and cops they are increasingly vested one challenge for instance is the increased participation of lists from various
Sectors fossil fuel industry as well as agroindustry sector in the last cups without any strong system at play so in a way a cup allows to capture the least common denominator of what all countries are ready for it’s always frustrating but you can also have other alliances of
Those who are good willing who are implementing implementing changes at a faster space and these types of alliances internationally can also be very inspiring uh to uh uh continue and keep momentum with the implementation of effective climate action there’s a strong tendency to insist on mitigation for international cooperation and it’s
Also key because at the moment there’s a major need for investments in the global South to support clean technology development there’s a potential but there’s a gap in terms of investment so a lot of recent efforts from the World Bank and other institutions development banks have been to try collectively to
Move uh funding resources that are available capital is there towards where it can make a difference and make it um available uh in those cases so cooperation in that case is highly needed the other example where cooperation is needed is related to adaptation in different regions of the
World we Face similar challenges but we come from different perspectives different approaches um and and approaches that bring together for instance not just governments but also cities from different contexts uh sharing their experience it is done between cities Network small cities as well as megapol like C40 is quite impressive because it
Allows to uh increase the capacity um and the knowledge basis of those who are Hands-On for instance in the te technical sectors of of these cities learning from the others and being able to not experiment and fail but learn from what has worked elsewhere so as to
Implement in a more effective way and international cooperation it matters for scientists it’s crucial it allows us to be better uh emulation learning from others and I think it’s also critical for students and being open to you know the various challenges and perspectives from various regions of the world it
Allows you to be a better human being and and and understanding sometimes your privileges