Locals say hurricanes destroyed around 50% of the mangroves in Mexico's Río Largartos nature park | Photo: A. Daschner, ZMT

28/04/2023 | On Monday (20/3/2023), the Intergovernmental Panel on Climate Change (IPCC) presented its synthesis report in Interlaken, Switzerland. The report serves as a basis for countries worldwide to agree on and implement further climate protection measures. This is what ZMT researchers say about the report:


Prof. Dr. Martin Zimmer, Head of the Ecology department and the working group Mangrove Ecology

"There can be no doubt (any more): Climate change is the result of human activities over the past centuries. It is in our hands to stop – or at least mitigate – further developments and their catastrophic consequences for humanity.
Climate change is closely linked to species extinction and the biodiversity crisis. Many species will not be able to keep up with environmental changes, adapt or migrate to other habitats – they will become extinct. There will be drastic changes in biotic communities and ecosystems. Humanity will be particularly affected in its dependence on natural resources.

The IPCC report also makes clear that climate change – and as a result increasing severe weather, droughts, storms and sea level rise – will affect people where they are particularly vulnerable. This is especially true for people in tropical regions, where the ZMT and its partners are conducting research to find solutions for sustainable use of natural resources and improved living conditions on the ground.
Our primary goal must now be to keep global warming below the 1.5 degree limit. The IPCC report clearly shows that the already noticeable changes above this threshold will have dramatic consequences. The window of opportunity for effective climate change mitigation measures is closing. However, it is not too late if we all ACT BOLDY AND CONSISTENTLY NOW: we must continue and intensify our search for solutions and take measures to remove carbon dioxide from the atmosphere and store it in the long term.

So far, such measures – if any – have mainly been undertaken on land. The ocean and its coastal ecosystems offer alternative and additional, very efficient solutions, but so far they remain largely unexploited. Within the framework of CDRmare, a BMBF-funded research mission of the German Marine Research Allicance, we are investigating the performance of various sea-based measures, but also their potential side effects, social acceptance and feasibility. Within this mission, the ZMT is focusing on blue carbon, and how and where land enhancement of vegetation-rich coastal ecosystems can be most effectively used to increase greenhouse gas emissions and storage."



Dr. Carolin Müller, working group Fisheries Biology

"With the launch of the latest IPCC report, humankind is obliged to translate the unequivocal words into tangible action across all areas of life: from renewable energy to green modes of transportation and, ultimately, sustainable production and consumption of living and non-living resources. The detrimental effects of climate change and plastic pollution are two sides of the same coin: on the one hand, these anthropogenically-induced stressors simultaneously harm marine ecosystems as well as the services they provide to the world’s population. On the other hand, plastic products are sourced from fossil fuels and throughout the entire life cycle of plastics, greenhouse gases are emitted, thereby significantly contributing to global climate change. Comparable to the effects of climate change as identified by the IPCC report, those who have contributed least to the global plastic pollution are disproportionately impaired."


Dr. Marleen Stuhr, (Interim) Head of the working group Geoecology and Carbonate Sedimentology

The new report undeniably shows that climate change is accelerating at an unprecedented rate, affecting land and seas. It illustrates effectively how our health is closely tied to the ocean’s and highlights the interlinkages between climate change, marine ecosystems and increased vulnerability of human societies. Ocean warming, increases in frequencies and magnitudes of heat waves and accelerating sea level rise cause irreversible losses to coastal ecosystems, substantially affecting livelihoods of coastal communities. Importantly, it confirms that small island developing states (SIDS) are among those contributing the least to climate change, but are at the same time some of the most vulnerable and strongest impacted. The report crucially emphasizes the importance and responsibility of global actions to specifically support such disproportionately affected regions, which supports the significance of our research in such tropical coastal ecosystems.

Some coastal ecosystems are now nearing tipping points due to climatic and other human stressors, after which hard limits of adaptation will be reached and some ecosystem-based adaptation measures are likely to lose their effectiveness. The IPCC’s AR6 clearly shows that coral reefs are amongst the most threatened by every tiny increase in warming, but that these ecosystems also act as cornerstones for effective adaptation and mitigation strategies, with various co-benefits for climate, biodiversity and society. Shoreline protection, habitat provisioning and food supply are some of the many services provided by healthy coastal ecosystems that are part of the solutions to tackle climate change. In contrast to previous reports, this constructive synthesis report focusses strongly on possible effective and often low-cost solutions that we do have available. In this regard, it emphasizes marine nature-based solutions such as marine protected areas, restoration and sustainable fisheries which offer many co-benefits for mitigation, adaptation and sustainable development, building various synergies with the SDGs. Yet, their effectiveness relies heavily on the immediate reduction of greenhouse gases emissions and the elimination of human-induced stressors on ecosystems. 

The escalating speed and hazards of global climate change in this report compared to the AR5 are highly alerting. Therefore, the IPCC underscores unmistakably that transformational changes must be carried out jointly and at a large scale, calling to international cooperation, while pointing to key barriers to adaptation, among these insufficient mobilization of finance (including for research), low climate literacy, limited research and/or slow and low uptake of adaptation science, and low sense of urgency. Further requesting the effective and equitable conservation of ~30-50% of land, freshwater and ocean areas, including presently near-natural ecosystems, to maintain the resilience of biodiversity and ecosystem services at a global scale, the report gives (challenging but) clear guidelines in what is needed, additional to the inevitable rapid reductions of GHG emissions.



Prof. Dr. Raimund Bleischwitz, Scientific Director of ZMT

"For me as an economist, the options for mitigating climate change are particularly interesting. The IPCC Working Group III (Response Strategies) has made a number of very good statements on many cost-effective and feasible options. In the steel industry, for example, there can be no climate protection without 'green steel' and no green steel without scrap recycling as for example in the recyling of old and unused ships."


Prof. Dr. Nils Moosdorf, (Interim) Head of the Biogeochemistry and Geology department and Head of the working group Submarine Groundwatter Discharge

The IPCC 2022 report, like its predecessors, shows us again what we can expect in the coming decades. The broad statements remain, but the level of detail and certainty has now increased. It is likely that the binding target agreed in Paris to limit global warming to 1.5°C will not be reached because the efforts of the states are not sufficient. On the current path, global warming will significantly exceed 2°C.

The consequences for our water cycle will be extreme. Groundwater often still acts as a buffer for longer dry periods, but in many regions of the world groundwater levels are falling. We are already talking about a global water crisis. In Germany – with a little over one degree of warming – we are experiencing drought situations hardly thought possible, in which groundwater sinks to such an extent that forests wither. Even Germany is now developing a water strategy for times of emergency.

Around the world, rainy seasons get mixed up and crop yields are lost. Extreme precipitation, droughts and forest fires will continue to increase and make some regions of the world uninhabitable, leading to migration and conflicts.

People in tropical regions are mostly not the causers of climate change, but the sufferers of its consequences. In tropical countries, adaptation strategies against the consequences of climate change must be implemented now, because the industrialised countries are not prepared to implement sufficient climate protection measures. Large investments are needed to protect against heavy rainfall and flooding and to make agriculture and drinking water supplies more resilient to droughts. It requires a lot of planning foresight, as the Earth system reacts rather sluggishly to changes and our current rapid changes will have long-lasting consequences. Since it will not be possible to adapt to all the impacts of climate change, some regions, especially along the currently densely populated coasts, will probably have to be abandoned in the future.

But the IPCC report also shows that we still have a chance to limit climate change to a level that remains bearable for us humans and protects the prosperity of future generations. As a geologist, I can say without exaggeration: the decisions we make now will shape living conditions on our planet for thousands of years. The IPCC report clearly shows why it is both financially and morally worthwhile to implement decisive action against climate change now. With my research, I would like to contribute to assessing the consequences of climate change, reducing them and thus also counteracting climate change. Based on this understanding, I hope that we as a society will do everything we can to limit climate change to a tolerable level and thus preserve a world worth living in for our children and grandchildren in the future.



Prof. Dr. Jan Haerter, Head of the Intgrated Modelling Department

"Extreme weather events and their changes often have a greater impact on people than fluctuations in the mean. In summary, AR6 reports that there is now a very high degree of certainty regarding the increase in heat extremes and the decrease in extreme cold. An increase in precipitation extremes is considered likely, even though there are still greater uncertainties here. This also applies to tropical cyclones and their precipitation and in particular the proportion of intense storms. Modelling and prediction of tropical convective precipitation is a current field of research, as small-scale processes are crucial here, which can only be inadequately described by climate models."

About the IPCC final report:

The Synthesis Report presented on Monday is the final document of the IPCC's 6th Assessment Cycle. It comprises six individual reports that have been published since 2018. This final report aims to synthesise and forcefully present all the findings. Further IPCC reports are to follow in five to seven years.

The Intergovernmental Panel on Climate Change (IPCC) was founded in 1988 by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO). It is an intergovernmental body consisting of representatives of the 195 member countries. On its behalf, researchers compile all findings on climate change, its impacts and future risks, as well as possibilities for adaptation and mitigation, in a cycle of five to six years. The next cycle is due to begin in the summer.