In September, a new report, “Well Under 2 Degrees Celsius,” was released by the Committee to Prevent Extreme Climate Change, a global think-tank group made up of scientists, policy makers and military experts. The premise of the report is to provide governments with practical solutions to implement the ambitions of the Paris Agreement and the Sustainable Development Goals adopted by the United Nations. It emphasizes the importance of glaciers in a global context by highlighting examples of melting glaciers in the Himalayas and Tibet.
To challenge the impacts of climate change, the group proposes a roadmap that highlights science-based policy pathways to give society an opportunity to limit global temperatures to safe levels and prevent a two-degree Celsius temperature increase. Solutions include decarbonizing the global energy system by 2050 and reducing short-lived climate pollutants. Unfortunately, climatic trends show that the global temperature has already warmed by 1 degree Celsius, the authors note. If emission levels stay at the current rate, we can expect to see a 1.5-degree Celsius increase in the next fifteen years, with a 50 percent probability of reaching 4 degrees Celsius by end of century.
The report uses the Arctic and Himalayas as prime examples of the severe impacts of temperature increases, as these regions continue to warm at nearly twice the global average. In the Himalayas and Tibet, for example, more than 80 percent of the glaciers are retreating, according to data collected by the authors. The South Asian monsoon, which provides the primary source of water for the glaciers, has decreased by around seven percent over the last fifty years.
When asked about the effect of a two-degree Celsius rise on glacial retreat, Eric Rignot, a co-author of the report and a professor of Earth system science at the University of California, Irvine, said, “A two degree Celsius above pre-industrial and even a 1.5 degree Celsius will not be sufficient to stop ice sheet melt. In fact, I think that a 1.5 degree Celsius will still commit us to multiple meter sea-level rise over the time scale of a couple of centuries. My hope is that once we are there, the world will realize that we can do better, sequester carbon and go back to a climate regime from the 1970s to 1980s, which in my opinion was okay for ice sheets.”
The authors note another concern for glaciers and snowpack in the Arctic and Himalayas: the deposition of black carbon from human activities like diesel combustion and biomass cooking. Black carbon decreases the snow’s albedo, causing surface warming and melting. If greenhouse gas emissions and black carbon deposition increase, these glaciers and mountain ranges will not be able to provide water for many people in the region who rely on connected river systems.
Due to emission trends not decreasing at a fast-enough rate, there is now only a 50 percent probability of achieving the two-degree Celsius goal, and there is a 10–20 percent probability of the warming exceeding three degree Celsius by 2100. To remain below the two-degree Celsius mark, global leaders would have to start on the carbon neutrality pathway by 2020, moving toward 100 percent clean energy as soon as possible. However, the political leaders, corporations, and the public tend to assume that there is more time to take action, the researchers contend, with many people unaware of the severity of the climate crisis.
Shichang Kang, one of the co-authors of the report and a professor at the Chinese Academy of Sciences, told GlacierHub, “As a scientist, I hope the international community will work together and take action as soon as possible. However, countries have diverse backgrounds and social and political issues. It seems that we can’t use one measurement for different countries.”
“It will be a challenge to remain below 1.5 degree Celsius,” Rignot added. “The problem is to transition to a carbon free economy fast enough. You cannot turn around an economy based on burning fossil fuel overnight to an economy using clean energy. This would be a catastrophe. You have to give it some time.” The report advises leaders to begin decarbonizing the global economy with low- or no-carbon technologies and renewables.
The authors equip world leaders to begin taking action by providing four building blocks to achieve these goals. The first building block includes fully implementing nationally-determined mitigation pledges under the Paris Agreement. The second scales up numerous sub-national and city climate action plans. The third includes reducing emissions of short-lived climate pollutants (SLCPs) by 2030 and decarbonizing the global energy system by 2050. The final building block aims to make scalable and reversible carbon dioxide removal measures, which can begin removing CO2 already emitted into the atmosphere.
Despite the fact that each country deals with climate change in a different way, climate change remains a serious problem that impacts the global community at large. The question now remains – will we reach our goal of staying below the 2°C mark?