“We’re running out of time”

20 Mar 2023

A dramatic turnaround is needed if we are to reach our climate goals, says LMU geographer Matthias Garschagen, one of the lead authors of the IPCC Synthesis Report.

Today, the Intergovernmental Panel on Climate Change (IPCC) is releasing its new Synthesis Report, which summarizes its last six major publications. LMU geographer Matthias Garschagen is one of two Germans among the 30 report authors from around the world. In our interview, he discusses the core findings.

Fort Myers on the west coast of Florida after Hurricane Ian.

© IMAGO / Cover-Images / Po3 Kruz Sanders / Us Coast 52026302

The last IPCC Synthesis Report was published over eight years ago. Does the new report view the global climate situation as more acute?

Matthias Garschagen: It does indeed. Firstly, it shows how climate change itself is advancing – and at a faster rate than we thought in the last reporting cycle. The warming and how it affects extremes, for example, is much more evident, and we’re now able to attribute extremes to climate change with greater confidence. The second very concerning point is that the risks and projected impacts of climate change – such as harvest losses and heat-related fatalities – are assessed to be higher. This is due to new research findings on the vulnerability and adaptation limits of systems and on feedback between various risk drivers. Societies and ecosystems are responding to a warming of 1.5 or 2 degrees Celsius more sensitively than we previously thought. At the same time, research is not just providing more knowledge on the problems, but increasingly also on possible solutions. As a matter of fact, the science tells us very precisely what we would need to do. Now it’s a matter of actually implementing the knowledge.

Has the tone in the document become more urgent?

I think so. We really are running out of time when it comes to climate change, and the tone is very clear and very urgent in this regard. If we want to meet the Paris goal of “well below two degrees,” we need a massive effort to turn things around, and this imperative is much clearer than it was eight years ago and the road ahead is steeper and more challenging than it was then.

It’s often forgotten that we’re also running out of time for climate change adaptation, as adaptations require long lead times when it comes to things like adapting seeds and flood-proofing our coastal cities. Here, too, alas, the urgency has become more acute than eight years ago, because the risks have intensified and we haven’t used the last years as effectively as we should and could have.


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When the most recent Assessment Report was published, you warned that it was getting tight. How much time do we have left?

If we really want to meet the temperature goal of the Paris Agreement, there is no time to spare. We have to really implement the turnaround without delay. We’ve made our job all the harder, as it can scarcely be done now without carbon dioxide removal from the atmosphere. The task we face as a society is getting larger and larger.

Moreover, we have to turn things around immediately in order to minimize the irreversible damage. Some politicians harbor the illusion that we could maybe be a bit laxer as regards climate action for the next one or two decades, and let global warming overshoot the 1.5 or 1.6 degree mark, or even beyond. In the second half of the century, we could then bring the temperature back down with the help of improved technologies for emissions reduction and carbon dioxide removal, according to this seductive line of thought.

Why shouldn’t we buy ourselves some time with these overshoot pathways?

Our report shows very clearly that these overshoot pathways come with very strong risks. Firstly, a temperature increase of more than 1.6 or 1.7 degrees produces damage that is partially irreversible. This refers to things like the melting of glaciers, the thawing of permafrost, or the loss of coral reefs due to marine heatwaves. In that case, it makes no difference for the ecosystem whether warming drops back down to 1.5 degrees later. Secondly, the overshoot sets natural processes in motion – such as the outgassing of methane when permafrost thaws – that subsequently make it harder to turn things around. That’s a very risky bet on the future.

With every year that we overshoot, with every tenth of a degree, the risks increase considerably that we will be unable to turn things around and that the damage we induce will be irreversible.

In recent times, presumably after most of the data for the IPCC reports was collected, the world has changed. Is the climate crisis being pushed into the background as a consequence of the Covid-19 pandemic, war, and the resulting energy crises?

This should not and must not happen. To pit one against the other and to say now that we’ve got to deal with a war first, and with a pandemic, so we should put climate change on the long finger – that would be the wrong conclusion.

Crises such as pandemics or food shortages driven by war, which are made worse in drought years exacerbated by climate change, but also phenomena such as social change, marginalization, poverty – these things have to be thought of in conjunction with each other. A good climate policy, which promotes solutions like renewables and decentralized power supply, is a good security policy at the same time. I believe this message is one people can really appreciate in these times. That there must be short-term trade-offs is of course only natural, but trading things off against each other in the medium term would be precisely the wrong course of action.


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What core statements does the IPCC make in its new report?

Essentially, they concern three main things:

Firstly, we can see very clearly that climate change is already having strong negative impacts. These effects are manifesting variously in different parts of the world, but everywhere they are significantly stronger than we had assumed perhaps only eight years ago, when we think of things like extreme weather events. The damage is already considerable now at just 1.1 degrees of global warming. This can no longer be denied.

Secondly, the report shows more clearly than previous reporting cycles that this has something to do with us humans. It has something to do with the way we treat this planet and pursue an unsustainable lifestyle. This cannot continue.

Another core message, however, is that we increasingly know what feasible, cost-efficient, and effective measures look like as regards reducing greenhouse gases, removing carbon dioxide from the atmosphere, and reducing risks. But we now need to get on with implementation without delay. The bundle of actions we currently have at our disposal will shrink and lose effectiveness with increasing time and warming. For example, certain adaptations in the agricultural sector will only work up to a specific temperature threshold.

Which ecospheres, climate zones, and regions of the world will be particularly affected?

The answer always depends somewhat on how different factors are weighted, but we can certainly make out some hotspots. In the polar regions, the effects are pronounced because changes are happening very rapidly there. Warming, for instance, is much higher than the global average, and therefore also the change in the natural systems. At the same time, these regions are home to communities that are very finely adapted to the existing ecological systems.

Another example is semi-arid regions, for which the projections show an increasing risk of droughts and harvest failures. This is a massive hotspot, because these are often regions that are also very socially vulnerable, due to factors such as widespread poverty, poor health systems, and poor education.

Another area that will face a particularly sharp rise in risks is coastal zones: typhoons and storm surges combined with sea level rises, salinization, heavy precipitation events, and heat. Large coastal cities are hubs for the global economy and for many local economies. Fundamentally restructuring these cities to make them secure for the future is a formidable challenge. And because we are undergoing strong urbanization worldwide, this affects an increasing proportion of the population and of the economic system.

Which problems are most urgent in the short term?

Actually, all of them. But I guess the single most pressing thing in the short term is to take effective steps to achieve a turnaround in climate protection. This is the first point.

Secondly, we should swiftly work toward establishing a global mechanism for dealing with the unavoidable losses and damages that will occur, above all in poorer countries. How can we do this in a way that is consistent with global justice, and how do we help these countries with adaptation? The current report shows much more clearly than the last one the extent of the chasm between the offers of support that are currently on the table and the assistance that would actually be needed.

What measures should be taken now?

In the area of climate change mitigation, the turnaround in the energy sector is key, but also in areas such as transport, buildings and agriculture. We actually have a quite good understanding which measures would be needed. The question is, for example, how we get to a carbon cap and trade system with appropriate prices to be fully effective.

In the area of climate adaptation, we should in the first instance utilize proven measures that are already in existence. Social security systems such as we take for granted in Germany, for example, do not exist in many regions of the planet. We know, however, that they have a large positive influence on the ability of societies to deal with basic vulnerability. After a natural disaster people do not fall completely through the net. Such tried-and-tested approaches contain so-called “low-regret” measures: a good social security system is beneficial even without climate change, and with it all the more so.

Alongside these measures, we also have to tackle questions for which the solutions are not at all apparent or that require difficult social negotiation processes. In coastal zones especially, people will have to ask themselves whether they should make very expensive investments in flood protection measures over the next three or four decades when we know that the measures will not even be effective in 80 years. We really must avoid such maladaptations – that is to say, poor or misguided adaptations – which actually increase risks.

Recognizing this and embedding this awareness in politics and law is vitally important. It won’t be long at all before these considerations become very practical and immediate – just think in Germany, for example, of cities sprawling into areas that will be prone to flooding in the future.

Is it still realistic that we could meet the climate goals we originally set?

They can still be reached, but only through drastic reductions and turnarounds. The 2-degree target is definitely still possible, but the 1.5-degree target only if we truly achieve a turnaround in emissions very quickly through drastic action and protect or even increase our natural and low-risk carbon sinks such as forests and wetlands.

We’ve created the problem and for too long we’ve missed the chance to take effective action. But it is still in our hands to do something about it. That is the number-one core message.

But this window of opportunity is closing, and quickly. And the burden we’re placing on future generations, if we fail to reach the right conclusions and be courageous in our actions, is brutal. This is something all of us should reflect on.

Prof. Dr. Matthias Garschagen ist Geographieprofessor an der LMU.


Prof. Dr. Matthias Garschagen is Chair in Human Geography and heads the Teaching and Research Unit for Human Environment Relations at the Department of Geography at LMU. He is one of the core authors for the synthesis report of the sixth assessment cycle. The Synthesis Report provides an overview of the state of knowledge on the science of climate change, emphasizing new results since the publication of the Fifth Assessment Report (AR5) in 2014. It is based on the reports of the three Working Groups of the IPCC, as well as on the three Special Reports.

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