Unchecked future greenhouse gas emissions, particularly of carbon dioxide from the burning of fossil fuels, will almost certainly lead to additional climate impacts such as further global warming, continued sea level rise, greater rainfall intensity, more serious and pervasive droughts, enhanced heat stress episodes, ocean acidification, and the disruption of many biological systems. The resulting inundation of coastal areas, severe weather impacts, and loss of ecosystem services will likely cause major negative impacts for most nations.It warns, however, that geoengineering should be considered a measure of last resort in coping with the problem:
Geoengineering could conceivably offer targeted and fast-acting options to reduce acute climate impacts and provide strategies of last resort if abrupt, catastrophic, or otherwise unacceptable climate change impacts become unavoidable by other means. However, geoengineering must be viewed with great caution because manipulating the Earth system is almost certain to trigger some adverse and unpredictable consequences. Furthermore, these impacts would almost certainly be distributed unevenly among nations and people, raising serious ethical issues. Research to date has not determined that there are large-scale geoengineering approaches for which the benefits would substantially outweigh the detriments.The statement recommends:
- Enhanced research on the scientific and technological potential for geoengineering the climate system, including research on the unintended as well as intended environmental responses.
- Additional study of the historical, ethical, legal, political, and societal aspects of the geoengineering issues.
- Development and analysis of policy options to promote transparency and international cooperation in exploring geoengineering options along with restrictions on reckless efforts to manipulate the climate system.