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IPCC report: three things you need to know

Philippe Drobinski
Philippe Drobinski
CNRS Research Director at the Dynamic Meteorology Laboratory (LMD*) and Professor at Ecole Polytechnique (IP Paris)
Patricia Crifo
Patricia Crifo
Professor of Economics at École Polytechnique (IP Paris), Researcher at CREST (CNRS) and Associate Researcher at CIRANO
Julie Mayer
Julie Mayer
Researcher and Lecturer at I³-CRG* at École Polytechnique (IP Paris)
Key takeaways
  • The latest IPCC report, published on 4 th April 2022, is a summary of the current situation of global warming, with the particularity of proposing solutions to combat this phenomenon.
  • The conclusion is that we can still act, but we must do so now.
  • The goal set by the Paris Agreement in 2015 seems to be achievable but requires a radical reduction in our GHG emissions in all sectors.
  • Limiting global warming requires major transitions in the energy sector, involving a substantial reduction in the use of fossil fuels.
  • Since the 5 th IPCC report, the costs of solar and wind power have fallen, and a growing range of policies and laws have improved energy efficiency and accelerated the deployment of renewable energy.

The lat­est IPCC report, pub­lished on 4 April 2022 1, is a sum­ma­ry of the cur­rent sit­u­a­tion of glob­al warm­ing, with the par­tic­u­lar­i­ty of propos­ing solu­tions to com­bat this phe­nom­e­non. All these rec­om­men­da­tions, togeth­er with esti­mates and sce­nar­ios for the best ways to imple­ment them, are pre­sent­ed as the path­way to avoid sce­nar­ios where glob­al tem­per­a­tures rise above 1.5°C – as described in the first report of this series, pub­lished in August 2021 2. The con­clu­sion is that we can still act, but we must do so now. Indeed, it shows that with­out imme­di­ate and mas­sive reduc­tions in green­house gas emis­sions, it will be impos­si­ble to keep glob­al warm­ing below 2°C.

Source: IPCC 3

“Glob­al tem­per­a­ture will sta­bilise when car­bon diox­ide emis­sions reach net zero,” explains Philippe Drobin­s­ki, pro­fes­sor of cli­mate sci­ence and direc­tor of the Lab­o­ra­toire de Météorolo­gie Dynamique and the Energie4Climate cen­tre at Insti­tut Poly­tech­nique de Paris. “For a warm­ing thresh­old of 1.5°C, this objec­tive for car­bon neu­tral­i­ty must be reached by the ear­ly 2050s. Lim­it­ing warm­ing to around 2°C requires that glob­al green­house gas emis­sions peak by 2025 at the lat­est, reduced by a quar­ter by 2030 and reach net zero car­bon diox­ide emis­sions world­wide by the ear­ly 2070s.”

It’s not too late

Patri­cia Cri­fo, pro­fes­sor of eco­nom­ics at École Poly­tech­nique and deputy direc­tor of the Energy4Climate cen­tre (IP Paris), says we can still act. “We often read that there is a cli­mate iner­tia of sev­er­al decades, and that efforts to reduce green­house gas emis­sions will some­how be futile in the short to medi­um term,” she says. “While many of the changes caused by past and future green­house gas emis­sions are indeed irre­versible (notably impacts on the ocean, ice caps and glob­al sea lev­els), the report points out that if we cut emis­sions sharply soon, we will see effects on air qual­i­ty with­in a few years, on glob­al sur­face tem­per­a­ture with­in about 20 years, and on many oth­er cli­mate impact fac­tors in the longer term. So, we can influ­ence our cli­mate future and every action counts.”

The tar­get, agreed in the Paris Agree­ment in 2015, still seems achiev­able, but requires a rad­i­cal reduc­tion in our GHG emis­sions, across all sec­tors – whilst bear­ing in mind that the impacts of var­i­ous sec­tors dif­fer in their emis­sions. This is the case for the agri­cul­ture, forestry, and oth­er land use (AFOLU) sec­tor, which accounts for 23% of glob­al GHG emis­sions with a total of 12 GtCO2 equivalent/year 4. How­ev­er, despite the large-scale emis­sion reduc­tions, as well as their enhanced soil absorp­tion, the sec­tor could achieve, the IPCC remains sto­ic. In the report we find, “[these large-scale reduc­tions] can­not ful­ly com­pen­sate for delayed actions in oth­er sectors”.

The energy transition must happen 

“Lim­it­ing glob­al warm­ing requires major tran­si­tions in the ener­gy sec­tor, involv­ing sub­stan­tial reduc­tions in fos­sil fuel use, wide­spread elec­tri­fi­ca­tion, improved ener­gy effi­cien­cy and the use of alter­na­tive fuels,” says Philippe Drobin­s­ki. “Since the 5th IPCC report, the costs of solar, wind and bat­tery pow­er have fall­en. A grow­ing range of poli­cies and laws have improved ener­gy effi­cien­cy, reduced defor­esta­tion rates, and accel­er­at­ed the deploy­ment of renew­able energy.”

Source: IPCC 5

The report points to the sig­nif­i­cant poten­tial for reduc­ing emis­sions from cities through reduced ener­gy con­sump­tion, elec­tri­fi­ca­tion of trans­port in com­bi­na­tion with low-emis­sion ener­gy sources and improved car­bon absorp­tion and stor­age using nature. Reduc­ing emis­sions in indus­try means using mate­ri­als more effi­cient­ly, reusing and recy­cling prod­ucts and reduc­ing waste. This must be accom­pa­nied by new pro­duc­tion process­es, low or zero emis­sion elec­tric­i­ty, hydro­gen and, where nec­es­sary, car­bon cap­ture and storage. 

He adds, “accel­er­at­ed and equi­table cli­mate action to mit­i­gate and adapt to the impacts of cli­mate change is essen­tial for sus­tain­able devel­op­ment. The options pro­posed would ben­e­fit bio­di­ver­si­ty, cli­mate change adap­ta­tion and secure liveli­hoods. Some can absorb and store car­bon and, at the same time, help com­mu­ni­ties to lim­it the impacts asso­ci­at­ed with cli­mate change.”

No individual effectiveness without structural change

Anoth­er angle pro­posed by the IPCC is reduc­tion in demand. To reduce our envi­ron­men­tal impacts, pro­duc­tion should no longer be based on quan­ti­ty, but only on what is need­ed. This includes changes in infra­struc­ture use, adop­tion of end-use tech­nolo­gies, as well as socio-cul­tur­al and behav­iour­al changes. Accord­ing to the IPCC, these “demand-side mea­sures, tak­en or to be tak­en, can reduce glob­al GHG emis­sions in the end-use sec­tors by 40–70% by 2050 com­pared to the ref­er­ence scenarios.”

Julie May­er, assis­tant pro­fes­sor at École Poly­tech­nique and researcher at I3-CRG (IP Paris), con­ducts research on the organ­i­sa­tion­al trans­for­ma­tions under­ly­ing the ener­gy and eco­log­i­cal tran­si­tion. She explains that “this is the first time that an IPCC report has giv­en so much space to the issue of sobri­ety. This shows that this con­cept is becom­ing essen­tial in the fight against glob­al warm­ing, and rein­forces its legitimacy.”

Through the term “ener­gy con­ser­va­tion”, the IPCC places sobri­ety as one of the levers of action to be under­tak­en. “This notion of sobri­ety con­cerns what indi­vid­u­als can change in their lifestyle, in dif­fer­ent areas, in order to reduce their dai­ly con­sump­tion. This can be done by lim­it­ing the use of elec­tron­ic devices, trans­port, or even by chang­ing one’s diet, with less meat, or more local consumption.”

“The IPCC report high­lights two key points of atten­tion: first­ly, that sobri­ety can­not be focused on indi­vid­ual behav­iour. Indeed, how can an indi­vid­ual be expect­ed to become sober if the sys­tem in which he or she lives is not? Sec­ond­ly, the report points out that efforts to reduce con­sump­tion, aim­ing at a sus­tain­able and fair tran­si­tion, will prob­a­bly not be the same from one pop­u­la­tion to anoth­er: mul­ti­ple fac­tors, such as the lev­el of wealth, must be tak­en into account.”

In gen­er­al, the IPCC experts, and more broad­ly the aca­d­e­mics who work on this notion of sobri­ety in var­i­ous dis­ci­plines, point to the need for a struc­tur­al and cul­tur­al change. “It is here”, she says, “that the social sci­ences have a very spe­cial role to play: the changes in behav­iour and lifestyles high­light­ed in the report raise a soci­o­log­i­cal, eth­i­cal, polit­i­cal and even philo­soph­i­cal ques­tion for which it is dif­fi­cult to envis­age a uni­ver­sal and objec­tive answer: what is just enough?”

Pablo Andres

1https://www.ipcc.ch/report/sixth-assessment-report-working-group‑3/
2https://www.ipcc.ch/report/sixth-assessment-report-working-group‑i/
3https://​www​.ipcc​.ch/​sr15/
4https://​www​.ipcc​.ch/​s​rccl/
5https://​report​.ipcc​.ch/​a​r​6​w​g​3​/​p​d​f​/​I​P​C​C​_​A​R​6​_​W​G​I​I​I​_​S​u​m​m​a​r​y​F​o​r​P​o​l​i​c​y​m​a​k​e​r​s.pdf