A Roadmap for Responding to Climate Change
Coordinators: Shiladitya DasSarma and Bruce Parker
Human activities have added more than 1.5 trillion metric tons of carbon dioxide to Earth’s atmosphere since the pre-industrial period, increasing its concentration from below 300 parts per million (ppm) to over 415 ppm today, and projected to surpass 1,000 ppm before 2100. This anthropogenic change is primarily due to burning fossil fuels which has resulted in the observable and ongoing climate change, including global temperature rise, warming oceans, melting polar ice, glacial retreat, sea level rise, increased extreme weather events and ocean acidification. The United Nations Intergovernmental Panel on Climate Change (UN IPCC) assessments have detailed the wide-ranging damages from climate change and the far-reaching and unprecedented interventions required to limit them. In 2016, the UN Framework Convention on Climate Change (FCCC) including 196 of the world’s nations committed to reducing greenhouse gases through the Paris Agreement. It is imperative that these commitments be adhered to and enhanced in the next three decades to avoid irreversible damages to Earth’s natural cycles and ecosystems and threaten human societies. Immediate actions that are necessary to avoid the worst damages include suspension of fossil fuel uses and their rapid replacement with carbon neutral (or carbon negative) energy sources, prioritizing renewable solar and wind energy which are now economically competitive. In addition, improvements in energy efficiency and reductions in energy use are urgently needed. Concurrently, careful management of carbon sequestration assets such as coastal marshes, forests and agricultural lands is essential. In order to achieve the aspirational goal of net-zero greenhouse gas emissions by 2050 or earlier, investments in research and development into promising technologies are urgently needed. Among new technologies, economically viable carbon capture technologies are important for drawdown of atmospheric carbon dioxide. An aggressive timeline is essential to avoid the worst damages from climate change that will otherwise result in the coming decades of the 21st century. These will include increasingly common and destructive weather events, food and water insecurity, and loss of habitats for large human populations. Urgent responses and actions are needed at the national, regional, and local levels as well as by institutional and individual leaders and citizens.