high hopes or high on hopium? the 1.5°C target.
what’s in it for you?
Understand what the 1.5°C and 2°C climate targets really meanLearn about the recent scientifc results which have already been plottedForm your opinion on what our collective climate goals should look like9-11 minute read
After two weeks of negotiations at the Le Bourget exhibition center, 195 countries agreed upon the following phrase by consensus:
“Recognizing the need to keep global average temperature increase well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change;”
We know the signed document of this COP21 (Climate Conference of Parties by the UN) conclusion as the Paris Agreement and ever since its inception the respective 2°C and 1.5°C target numbers are being embedded into our collective consciousness. However, the way politicians, activists, businesses, or media in general word those numbers, seem to vary widely.
What do those targets really mean? Are they an honourable and feasible goal that rightfully emphasizes urgency? Or are they delusional and dishonest, green washing reality, and hindering functional pathways for climate change mitigation and adaptation?
Fig 1. Snapshot on the variety of headlines with a different 1.5°C target messaging.
what would “keeping the 1.5°C target alive” look like?
Let’s quickly (over)simplify climate change and the warming targets:
Greenhouse gases (GHG) in the atmosphere trap heat and increase overall global temperatures. Total emissions are generally measured in Carbon Dioxide Equivalent (CO2e) to unify the global warming potential of different GHG sources.
The scientific community exhaustively calculated and agrees that human activity is the main contributor to global GHG emissions (beyond the naturally occurring emissions) with ~55Gt (2021) of CO2e per year, roughly ¾ of which come from carbon dioxide (CO2) [1].
The 1.5°C and 2°C warming targets refer to pre-industrial temperature levels (average 1850-1900) and global temperature have already risen by around 1.1°C as of today [2].
Knowing this temperature increase and how much GHG we have already emitted, one can extrapolate how much more emissions we can “allow” ourselves in order to not increase global temperatures by another ~0.4°C, overshooting the 1.5°C target
The MCC Think Tank (founded by the Potsdam Institute for Climate Impact Research (PIK)) diligently did the math and calculated a global carbon budget for our remaining CO2 emissions allowance: ~266Gt for the 1.5°C target (as of writing this April 2023).
They also provide a respective carbon clock, showing when we will use up our carbon budget given current global emissions: middle of 2029. So about 6 years to “keep the 1.5°C target alive” compared to almost 24 years for the 2°C scenario.
Okay but that’s assuming current carbon emissions, right? What emission trajectory are we on given the last few years of policy commitments, technological developments, etc.?
what would our pathway to 1.5°C look like?
Fig 3. UNEP Emissions Gap Report 2022 showcasing the vast divergence from the 1.5°C pathway.
IPCC’s 6th assessment report (AR6) published in March this year shows our best guess trajectory of our currently implemented policies. We are heading to a 3.2°C world [2].
The global authority for the environment United Nations Environment Programme (UNEP) also released their Emissions Gap Report showing how much we are diverging from a 1.5°C (and 2°C) pathway (see Graphic 3). While their current policies scenario is a bit more positive (heading to a 2.8°C world), we will still massively overshoot the required yearly GHG emission reduction target down to ~33Gt by 2030 by actually increasing emissions up to ~58Gt (including carbon capturing offsets). A 25Gt emission gap, spending ~175% of our actual budget every year. And here is where the financial budget analogy ends as we cannot afford to cover the debt we are making. Even their best-case scenario of fully implemented conditional Nationally Determined Contributions (NDCs), so the reduction target commitments stated by individual countries, and additional net zero commitments would still lead to 1.8°C warming [4]. However, UNEP themself do not view this scenario as credible. The verdict of our global authority for the environment is hence that there is no credible pathway to limiting global warming to 1.5°C.
how confident are we on this?
It is our scientific best guess – so arguably as confident as it gets. However, the pathways do show a confidence interval of 66%, so there is a range with a corresponding level of uncertainty. The global climate is incredibly complex due to, e.g., tipping points such as the melting of permafrost in Greenland or the change of currents like the gulf stream - consequences of which are most often hard to predict. Global warming of X°C therefore also refers to an overall average. In certain parts of the world, temperatures have already increased by ~4°C whereas others remained stable or even cooled down slightly [5]. Also, technological breakthroughs or societal events can always significantly impact the trajectory; the development of carbon capture technology or COVID (even though the impact was not as big as some might have assumed, see Graphic 3’s dip in 2020-2021) come to mind. But nonetheless, the 1.5°C is technically still achievable.
so now what?
Based on these publications, we could ask ourselves two questions for the practical and philosophical consequences of our global climate ambition, communication, and policy making.
Firstly: How should we address and balance mitigation (reducing net emissions) and adaptation (preparing for climate change consequences) with this outlook? The Paris Agreement and Green Climate Fund both call for a 50:50 balance between the two. The rationale behind this even split appears to be more of a compromise as no agreement for a compelling case using an uneven split was found yet [6]. In reality, however, global climate financing currently prioritises mitigation over adaptation with a 63:37 ratio [7].
Secondly: Should we still communicate the 1.5°C target motivating society to go above and beyond for revolutionary climate action? Or do we compromise credibility by being dishonest in the light of scientific forecasts and abandon the 1.5°C to focus on the, still ambitious, 2°C target?
In my opinion, it is time to commit to distinct goals which are more realistic, graspable, and actionable, based on the 2°C pathway. I am aware how much worse the consequences of a 2°C world will be compared to 1.5°C [8]. There is also an important consideration of potentially discrediting and harming ambitiously climate active organisations and institutions whose agendas are based on a 1.5°C target. Letting go of a strong political commitment made by almost all countries worldwide through the Paris Agreement is certainly a risky direction with far reaching consequences - especially as the 1.5°C is technically still achievable! However, I do not think it is worth the moral and psychological price we pay for “keeping it alive”. With our most credible scientific institutions not seeing a realistic way to achieve this goal, how should we start building authentic and credible action plans? As a global society, I believe that we desperately need more positive messaging and reinforcement on the topic of climate action rather than a seemingly ever increasing “doomsday scenario” messaging, accelerating phenomena such as climate depression [9]. The topic of the psychology behind communicating climate goals surely deserves its own article but in a nutshell: for long-term goals to be motivating, some form of a positive feedback loop of tangible achievements needs to be established. And our current track record does seem ill-equipped for that, especially when using 1.5°C as the benchmark with a world that has already warmed by 1.1°C.
For starters, an average temperature increase is not very tangible or urgent sounding, implies a lot of different consequences for different regions and people, and might mean even less to you depending on the temperature scale you use on a daily basis. I am not implying that we should abandon the incredibly vast, useful, and important science built around the 1.5°C and 2°C targets “intellectually”. However, rather than emphasizing this abstract, long-term, and politically set rather than scientifically determined goal, focusing on more tangible short- to mid-term goals such as, e.g., yearly GHG emissions on a given country, corporate, or even individual basis that are in line with the respective reduction pathway, could massively empower us on a daily basis. These kinds of smaller step-by-step goals are way more likely to be (at least partly) achieved and therefore create moments of success to celebrate milestones that in turn can generate motivation and positive momentum. I sincerely see a unique opportunity for our global society on the topic of climate change if we change our mindset and narrative on the topic - more on that in the next article!
But what are your thoughts on our global warming targets? Which one of the headlines of the initial Graphic 1 resonates with you? 1.5°C climate target - invest or divest?
our two cents
The world has already warmed by 1.1°C and there is strong scientific consensus that no realistic pathway to limiting global warming below 1.5°C exists. However, this does not mean doomsday has come - let's rethink our communication and reframe our goals.-
[1] Ritchie, Hannah. “CO₂ and Greenhouse Gas Emissions.” Our World in Data, May 11, 2020. https://ourworldindata.org/greenhouse-gas-emissions.
[2] IPCC. “AR6 Synthesis Report: Climate Change 2023 — IPCC,” n.d. https://www.ipcc.ch/report/sixth-assessment-report-cycle/.
[3]“CO₂ and Greenhouse Gas Emissions.” Our World in Data, May 11, 2020. https://ourworldindata.org/co2-and-greenhouse-gas-emissions.
[4] UNEP - UN Environment Programme. “Emissions Gap Report 2022,” n.d. https://www.unep.org/resources/emissions-gap-report-2022?gclid=Cj0KCQjwla-hBhD7ARIsAM9tQKtkwv0dhtA4MVxhKFQ4pndSskahbCjF5nBfYLkIlcCsaPb2NKho3jUaAtAxEALw_wcB.
[5] NASA Earth Observatory. “World of Change: Global Temperatures,” n.d. https://earthobservatory.nasa.gov/world-of-change/global-temperatures.
[6] Eurodad. “Where Do Things Stand on the Global US$100 Billion Climate Finance Goal?,” September 7, 2022. https://www.eurodad.org/where_do_things_stand_on_the_global_100_billion_climate_finance_goal.
[7] Fund, Green Climate. “GCF in Brief: Adaptation Planning.” Green Climate Fund, n.d. https://www.greenclimate.fund/document/gcf-brief-adaptation-planning.
[8] Levin, Kelly. “Half a Degree and a World Apart: The Difference in Climate Impacts Between 1.5˚C and 2˚C of Warming.” World Resources Institute, n.d. https://www.wri.org/insights/half-degree-and-world-apart-difference-climate-impacts-between-15c-and-2c-warming.
[9] Schwaab, Lukas, Nadja Gebhardt, Hans-Christoph Friederich, and Christoph Nikendei. “Climate Change Related Depression, Anxiety and Stress Symptoms Perceived by Medical Students.” International Journal of Environmental Research and Public Health 19, no. 15 (July 27, 2022): 9142. https://doi.org/10.3390/ijerph19159142.
