资源环境科技发展态势分析平台

Why is Earth's climate changing? It is considered extremely likely that global warming is caused by a rise in greenhouse gases such as carbon dioxide and methane due to human activity. How these changes impact the numerous processes taking place in Earth's climate system remains uncertain. Renowned climate researchers and representatives of international organisations will gather from 17 to 19 April 2018 to discuss how aviation and aerospace research can contribute to improving our understanding of atmospheric processes, and how the negative implications of climate change can be addressed. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) has organised the conference for the second time in collaboration with the United Nations Office for Outer Space (UNOOSA).

Satellite data to map climate changes on the ground and in the atmosphere

The climate agreements of Paris (COP21), Marrakesh (COP22) and Bonn (COP23) set the target of reducing greenhouse gas emissions to a level that will restrict global warming to less than two degrees Celsius. "The research conducted at DLR – especially in aviation and space – contributes to a better understanding of the complex processes unfolding in the atmosphere, and by doing so builds the foundation for effective climate protection. Earth observation and atmospheric research yield crucial data that we use to map climatic implications and global changes," says Hansjörg Dittus, DLR Executive Board Member for Space Research and Technology. "By organising this conference, DLR is providing a discussion forum for international scientists and organisations to share their views on the current state of research."

Satellite data accuracy is increasing steadily

The Sentinel-5P (Sentinel-5 Precursor) satellite has delivered accurate data on air quality, ozone and greenhouse gases since 2017. Scientists can use the data acquired by the satellite to identify sources of air pollution, for instance coal-fired power plants, refineries or even volcanic eruptions. They are also able to observe changes in climate gas concentrations and hence assess the effectiveness of political measures. Sentinel-5P is part of the European Earth observation programme Copernicus, and the atmospheric data and map products it acquires are freely accessible to all interested parties. EarthCARE (Earth Cloud, Aerosol and Radiation Explorer), a European-Japanese mission, is scheduled for launch in 2019. Its goal is to record the impact of clouds and aerosols on Earth's global radiation balance. EarthCARE will combine measurements on the influence of solar radiation at the outermost boundary of the atmosphere with measurements of clouds and aerosol characteristics, hence contributing to a better understanding of how aerosols and clouds affect radiation and the feedback processes within the Earth-atmosphere system. In addition, scientists use numerous Earth observation satellites to acquire increasingly accurate information on global changes, for instance land development, soil condition, soil moisture or ground uplift and subsidence.

Mapping and minimising the climate effects of aviation

Aviation contributes roughly 12 percent to the transport sector's total carbon dioxide emissions. This is compounded by the cloud cover induced by condensation trails (contrails). These clouds can heat up or cool down the atmosphere, depending on the position of the Sun and its relation to the underlying ground. Research so far has indicated that the warming effect is more prevalent at a global level. "At DLR, we conduct targeted aircraft measurement campaigns and model studies on climate impact within the aviation sector," says Rolf Henke, DLR Executive Board Member for Aeronautics Research. "Deployed worldwide, the HALO and Falcon research aircraft deliver data on climate gases and the physical properties of clouds that provide an important building block in the development of improved climate models." For instance, DLR researchers have, for the first time, managed to incorporate measurement data from the HALO ML-Cirrus mission into a climate model of contrail cirrus clouds caused by air transport. In particular, the model delivers the first data on coverage levels, optical properties and radiative forcing of the ice clouds produced by aircraft. In an international partnership with NASA involving a joint measurement campaign with the DLR A320 ATRA and the NASA DC 8 in January 2018, DLR examined how reduced soot emissions from alternative aviation fuels can lead to changes in ice crystals and hence to a reduced climate warming effect.

Mitigation of the aviation sector's climate impact is a focus area for DLR research into flight scheduling and the development of new technologies to protect the climate. "Within CleanSky 2 , we are already cooperating with European partners in a concerted effort to develop green aviation technologies that protect the climate," Henke emphasises. "Here, DLR is among the largest research partners and plays a leading role." Clean Sky 2 seeks to significantly advance technological development and hence make a substantial contribution to an approximately 75 percent reduction in carbon dioxide emissions within the aviation sector by 2050. "We will engage with consortiums at national, European and international levels to continue leveraging our research efforts to map and reduce the climate impact of air transport," says Henke, adding: “We are also heavily involved in the development of innovative aircraft for rescue and disaster management missions. The assistance they provide will become increasingly urgent as climate change progresses."

One hundred participants have registered to attend each of the three days. The international scientists come from 10 countries, namely Germany, France, Switzerland, Great Britain, Italy, the Netherlands, Austria, the USA, Cameroon and Botswana. This conference will offer an opportunity to exchange their experiences in more than 30 discussions. The 2018 Conference on Climate Change is organised in line with sustainability principles; for instance, by cooperating with regional catering partners that demonstrably provide a highly sustainable service. In addition, local shuttle services will not be required due to the booking of hotel accommodation close to the venue.