April 2014, Volume 20, Number 2
The United Nations Framework Convention on Climate Change hopes to achieve agreement among world leaders in Paris in December 2015 to limit the increase in global temperature to two degrees Celsius or 3.6 degrees Fahrenheit above preindustrial levels. In order to keep global temperatures from rising more than two degrees Celsius, atmospheric concentrations of carbon dioxide, the main greenhouse gas, would have to stay below 500 parts per million. Carbon dioxide levels are currently 400 parts per million and rising.
The Paris agreement, scheduled to go into effect in 2020, would replace the 1997 Kyoto Protocol with a binding commitment to reduce carbon dioxide emissions.
Many of the technologies that could reduce carbon emissions require major subsidies to become commercially viable. For example, bioenergy with carbon capture and storage (Beccs) would use biomass from crop and forest production to produce energy. Plants remove carbon dioxide in the air through photosynthesis and store the carbon in plant tissues, which can be burned to produce energy. The carbon released in the burning can be captured and stored underground, which lowers the level of carbon dioxide in the atmosphere.
Fossil fuels are created from vegetation that is millions of years old, so capturing the carbon released by burning fossil fuels does not reduce current carbon dioxide levels.
The Intergovernmental Panel on Climate Change, the scientists who provide the analysis to guide world leaders, released a report in March 2014 on the impacts of failure to slow carbon emissions in order to keep the rise in the global average temperature of no more than 3.6 degrees Fahrenheit (2 degrees Celsius) above the preindustrial level.
The IPCC warned governments that they have no time to lose to slow global warming, and emphasized that governments continue to subsidize fossil fuels rather than shift to cleaner energy. They pointed to China, where new coal-fired power plants are being built to satisfy the growing demand for electricity, despite the rapidly falling cost of wind and solar power. The IPCC acknowledged that a faster shift to so-called clean energy would slow economic growth.
The IPCC report criticized industrial countries for "outsourcing" carbon emissions to developing countries via trade, noting that importing goods from China means that the emissions involved in their production occurred in China. The report noted that the world's food supply is threatened by global warming, which could result in death or injury on a widespread scale, probable damage to public health, displacement of people and potential mass migrations.
The report emphasized the need to both slow global warming and to adapt to a hotter planet. It emphasized that the world's poorest peoples, who contribute little to global warming, are likely to bear much of the cost of adapting to climate change. The World Bank believes poor countries need $100 billion a year to adapt to climate change, but they are receiving only a few billion a year from richer countries. This "adaptation deficit" was highlighted by advocates of more development assistance.
The IPCC issued a report in September 2013 on the physical science of climate change. The March 2014 report deals with the impacts of climate change, efforts to adapt to these impacts, and the vulnerability of human and natural systems. A third report in April 2014 will deal with policies to limit the rise of greenhouse gases.