The world has two basic tracks for keeping greenhouse gas emissions from rising dangerously high: take steady action now to taper off emissions, or allow emissions to increase over the next 10 to 20 years and then bring them down sharply, the head of the Intergovernmental Panel on Climate Change told a gathering at the World Bank ahead of Earth Day.
Delaying action raises the risks and the cost.
“If you allow emissions to increase, the impact of climate change will become progressively more serious, and the technologies that you would have to put in place to reduce emissions very sharply would be that much more expensive,” IPCC Chairman Rajendra Pachauri said as he gave the Robert Goodland Memorial Lecture, in honor of the World Bank’s first ecologist.
To avoid the worst effects of climate change, the world will have to reduce greenhouse gas emissions significantly by 2050 and then become carbon neutral by 2100, the latest IPCC report says.
That will require a range of technologies that by 2100 can remove carbon dioxide from the atmosphere, including carbon capture and storage, a developing technology that buries carbon dioxide but carries risks, Pachauri said. The rate of improvement in energy efficiency would need to increase much more rapidly, and the share of low-carbon energy from renewable sources would have to triple or quadruple by 2050. There would be opportunities for nuclear power and for bioenergy or fossil energy, but only with carbon capture and storage.
Cost of Inaction
The challenge the world faces without action is spelled out across the report, written by 235 scientists from 39 countries, with input from 180 contributors and more than 800 experts who reviewed the reports.
Climate change is raising the risks to food security, livelihoods, and human health, not only through the increasing frequency and intensity of heat waves and extreme precipitation events but also as a result of increases in vector borne diseases whose carriers thrive under warmer conditions. The reports describe three decades of successively warmer global temperatures, sea levels that have risen on average 19 cm since 1900, and rising CO2 emissions.