The top 10 insights in climate science in 2020, selected by 57 leading global researchers

The 2020 state of the climate report was presented by Patricia Espinosa, Executive Secretary of the United Nations Framework Convention on Climate Change (UNFCCC). It has been held every year since 2017 and is aimed at the international scientific-political community. The only representative from Spain is the ecologist Josep Peñuelas, CSIC researcher at CREAF.

The document is the result of collaboration between Future Earth, the Earth League and the World Climate Research Programme (WCRP). The impact of climate change is the most prominent aspect, which threatens to be as abrupt and far-reaching in the coming years as the current pandemic. The paper discusses everything from improved modelling that reveals the need to drastically reduce emissions to meet the Paris Agreement, to the increasing use of human rights litigation to catalyse climate action. In addition, the report also points to growing risk factors, such as permafrost emissions that are currently unaccounted for, concerns about weakening carbon sequestration in terrestrial ecosystems, and the impacts of climate change on freshwater and mental health.

"This series is a key part of our mission to bring the latest science to decision-makers to help accelerate transitions to sustainability," says Wendy Broadgate –director of Future Earth's Global Centre in Sweden. "The worsening of forest fires, intensifying storms and even the current pandemic are signs that our relationship with nature is deteriorating, with deadly consequences.

While confirming the continued amplification of major environmental impacts, the report also points to opportunities arising from new insights into the economics and governance of climate change. The year 2021 will be critical for action if the world is to achieve the goals of the Paris Agreement and preserve humanity's critical climate niche.

Josep Peñuelas, a CSIC researcher at CREAF, is the only representative of Spain among the 57 scientists from 21 countries who have compiled the 10 keys to climate in 2020. The report is published annually since of 2017 and is aimed at the international political science community.

The investment costs in 2020-2024 to meet the Paris Agreement are estimated to be only about half of the post-pandemic stimulus packages that have been announced so far. However, the report notes that governments are failing to seize the opportunity presented by current events for positive change. For example, G20 governments are spending 60% more on fossil fuel-based activities than on sustainable investments.

Detlef Stammer –chair of the Joint Scientific Committee of the World Climate Research Programme and professor at the University of Hamburg– points out that "to cope with future climate change we need detailed knowledge about how the climate system works, and we need to develop actionable regional and local information and impacts".

The top 10 new insights in climate science in 2020:

1. Improved understanding of Earth’s sensitivity to carbon dioxide strengthen support for ambitious emission cuts to meet Paris Agreement. The climate’s sensitivity to carbon dioxide – how much the temperature rises with a certain increase of emissions – is now better understood. This new knowledge indicates that moderate emission reductions are less likely to meet the Paris climate targets than previously anticipated.

2. Emissions from thawing permafrost likely to be worse than expected. Emissions of greenhouse gases from permafrost will be larger than earlier projections because of abrupt thaw processes, which are not yet included in global climate models.

3. Tropical forests may have reached peak uptake of carbon: Land ecosystems currently draw down 30% of human CO2 emissions due to a CO2 fertilization effect on plants. Deforestation of the world’s tropical forests are causing these to level off as a carbon sink.

4. Climate change will severely exacerbate the water crisis. New empirical studies show that climate change is already causing extreme precipitation events (floods and droughts), and these extreme settings in turn lead to water crises. The impact of these water crises is highly unequal, which is caused by and exacerbates gender, income, and sociopolitical inequality.

5. Climate change can profoundly affect our mental health: Cascading and compounding risks are contributing to anxiety and distress. The promotion and conservation of blue and green space within urban planning policies as well as the protection of ecosystems and biodiversity in natural environments have health co-benefits and provide resilience.

6. Governments are not seizing the opportunity for a green recovery from Covid19. Governments all over the world are mobilizing more than US$12 trillion for Covid19 pandemic recovery. As a comparison, annual investments needed for a Paris-compatible emissions pathway are estimated to be US$1.4 trillion.

7. COVID-19 and climate change demonstrates the need for a new social contract. The pandemic has spotlighted inadequacies of both governments and international institutions to cope with transboundary risks.

8. Economic stimulus focused primarily on growth would jeopardize the Paris Agreement. A Covid19 recovery strategy based on growth first and sustainability second is likely to fail the Paris Agreement.

9. Electrification in cities pivotal for just sustainability transitions. Urban electrification can be understood as a sustainable way to reduce poverty by providing over a billion people with modern types of energy, but also as a way to substitute clean energy for existing services that drive climate change and harmful local pollution.

10. Going to court to defend human rights can be an essential climate action. Through climate litigation, legal understandings of who or what is a rights- holder are expanding to include future, unborn generations, and elements of nature, as well as who can represent them in court.

The relevance of these 10 points is explained by Peter Schlosser -vice president and vice chancellor of the Julie Ann Wrigley Global Futures Lab at Arizona State University and co-chair of the Earth League. "It is critical to inform the decision-making process for immediate action, given the urgency of reducing greenhouse gas emissions and removing carbon from the atmosphere to prevent our planet from overheating."

"Our entire world is affected by the climate crisis and every continent, country, city and town depends on how well we manage the Earth's natural carbon sinks -that is what the overwhelming scientific evidence shows," says Johan Rockström, co-chair of the Earth League and co-chair of the Future Earth Advisory Committee. "From all these scientific insights, a political insight should emerge: if we are to have a chance of stabilising our climate, for the sake of our own security, the last chance to reduce greenhouse gases is now”.