Earth observation supports latest UN climate report

The latest edition of the sixth assessment report of the United Nations Intergovernmental Panel on Climate Change (IPCC) was published on March 20th. The report warns that the planet has already warmed by 1.1°C above pre-industrial levels, leading to more frequent and intense extreme weather events that are having increasingly dangerous impacts on nature and people in all regions of the world.

The report includes a larger contribution of Earth Observation data than its previous iterations to provide the physical evidence of Earth’s changing climate system – from rising sea levels, growing greenhouse gas emissions and melting sea ice.

The synthesis report summarizes the main findings of six reports published during its sixth assessment cycle and provides a comprehensive overview of global climate knowledge.

Previous reports have highlighted the challenge of keeping warming to 1.5°C, but five years later the challenge has become even greater due to rising greenhouse gas emissions. The current pace and scale of what has been done, as well as current plans, are not enough to tackle climate change.

More frequent and intense extreme weather events are having increasingly dangerous effects on nature and people in all regions of the world. More heat waves, heavier rainfall and other extreme weather events further increase risks to human health and ecosystems. To avoid the worst consequences, the global community has been urged to almost halve emissions by 2030.

Clear way forward

The report stresses the need for urgent climate action to ensure a future worth living for all of us. There are several viable and effective options for reducing greenhouse gas emissions and adapting to human-caused climate change that are now available.

The report finds that solutions lie in climate-resilient development. This involves integrating action to adapt to climate change with action to reduce or avoid greenhouse gas emissions in a way that provides broader benefits in promoting sustainable development for all.

Political commitment, coordinated policies, international cooperation and inclusive governance are all important for effective and equitable climate action.

Our climate, our ecosystems and our society are all interconnected. Effective and equitable protection of around 30% to 50% of the earth’s land, fresh water and oceans will help ensure a healthy planet.

Satellite support

Satellite observations are an integral part of evidence-based assessment of climate change impacts on terrestrial, freshwater, oceanic, coastal, mountainous and polar systems, particularly in areas where in situ measurements are not available.

The role of Earth Observation has evolved to support national institutions and stakeholders to build resilience and work towards their net zero commitments.

Simonetta Cheli, Director of Earth Observation Programs, says: “Climate records have shown us that the window to action is closing: melting glaciers, recent droughts and floods in Europe, and more extreme weather events are all telling us that now is the time to act.

“Our role as ESA is to provide world leaders and policymakers with climate data, space applications and solutions to help us achieve carbon neutrality in time for our planet to thrive again.”

In particular, through its Climate Change Initiative (CCI), ESA contributes to long-term satellite observation datasets that serve as important physical evidence in the latest state-of-the-art assessment.

Efforts by ESA to provide evidence to assess climate have increased. Since the last review cycle, the number of articles contributing to the report has tripled – 150 articles produced by the CCI have been cited more than 400 times. More than 30 researchers working on this ESA initiative contributed directly to the report as lead or contributing authors or reviewers.

greenhouse gas emissions

Limiting human-caused global warming requires a significant reduction in carbon dioxide, methane and other greenhouse gas emissions. Net-zero greenhouse gas emissions, if sustainable, are expected to lead to a gradual decline in global surface temperatures.

Satellite data is fundamental to ensuring we have a clearer picture of the emissions caused by human activities that are causing climate change. The Copernicus mission for anthropogenic carbon dioxide (CO2M) aims to measure exactly that. Specifically, the mission will be the first to measure anthropogenic carbon dioxide in the atmosphere.

Scientists have already found new ways to compare and verify national greenhouse gas inventories with independent satellite observations.

Extreme events

Since the IPCC’s Fifth Assessment Report in 2014, evidence of observed changes in extreme events such as heat waves, heavy rainfall, droughts and tropical cyclones, and in particular their attribution to human influence, has continued to strengthen heat waves and droughts.

Extreme events will pose serious threats to the livelihoods and stability of many nations around the world, particularly those in more vulnerable communities, in the years to come.

The recently launched third-generation Meteosat satellites will predict how rapidly evolving and highly dangerous weather events will develop and help save lives. This will be done via “nowcasting,” which refers to the near-real-time monitoring and forecasting of severe storms as they develop and evolve.

sea ​​level rises

According to the report, global mean sea level has risen by 20 cm since 1901, with the average rate of rise accelerating to a peak of 3.7 mm per year since 2006.

Sea level rise is inevitable over centuries to millennia due to continued warming of the oceans and melting of the ice sheet, and sea levels will remain elevated for thousands of years. However, deep, rapid and sustained reductions in greenhouse gas emissions would limit further acceleration of sea level rise and the projected long-term obligation to sea level rise.

Satellite altimetry techniques allow for accurate measurement of sea level change. Launched in 2020, the Copernicus Sentinel-6 Michael Freilich satellite is capable of measuring tiny differences in sea surface elevation from space using the latest radar altimetry technology.

The mission now provides the world’s most accurate data on the changing height of the sea surface.

Accelerating action

Earth Observation data has been essential to the preparation of the IPCC reports and will be essential to the 2023 and 2028 United Nations Global Inventories. In addition, the exploitation of space resources and technologies offers untapped potential that can be integrated and developed into further space solutions in areas such as energy, agriculture and urban planning.

Further action is needed to leverage and build on existing and planned activities to maximize impact and provide solutions urgently. ESA’s Space for a Green Future Accelerator is a direct response to the global climate and environmental crisis to support a sustainable green transition towards a carbon-neutral, resource-efficient and resilient society.

Working with ESA’s key partners, the accelerator will provide actionable intelligence, assess policy implementation scenarios and provide tailored services to achieve carbon neutrality by 2050.