In a recent article The Economist covered developments in geoengineering, both scientific and political.
Countries look at ways to tinker with Earth’s thermostat
Selected excerpts:
Countries look at ways to tinker with Earth’s thermostat
Selected excerpts:
Under the Paris Agreement, governments have pledged to keep average global warming to “well below” 2°C above pre-industrial levels and to try to limit maximum warming to 1.5°C. Many see these targets as wishful thinking: the planet is already roughly 1°C warmer than it was in pre-industrial times, global greenhouse gas emissions are still on the rise and national pledges to cut them fall short of what is needed to hit the 2°C target, let alone 1.5°C.
[...]
So far, most studies have modelled a “fully” geoengineered world in which CO2 concentrations are doubled compared with current or pre-industrial levels, and all the resulting warming is counterbalanced by a stratospheric sunshade. Instead, Peter Irvine of Harvard University and his colleagues simulated a partial sunshade. They were able to eliminate half the warming effect of doubled CO2 concentrations while stabilising the water cycle.
[...]
The researchers say their study is more relevant to real policy decisions because it shines some light on what could be done by, for instance, combining solar geoengineering with efforts to cut greenhouse gas emissions. But all this would require international consensus, and obtaining that may be a fantasy.
The barriers to unity were on display in Nairobi. In 2010 the Convention on Biological Diversity advised against geoengineering activities “until there is an adequate scientific basis” to justify them, but America is not a party to that convention. It was represented at unea. However, several delegates told this newspaper that America and Saudi Arabia opposed the Swiss proposal to review geoengineering, preferring the issue to be assessed by the Intergovernmental Panel on Climate Change (ipcc), which is due to include something about the technologies in its next big report, expected in 2021.
[...]
The only reason the world may need geoengineering is that talks about cutting emissions have gone on so long but achieved so little. Yet in Nairobi delegates could not even commission a report. Geoengineering, the toolbox that a decade ago nobody wanted, could end up stuck in the same international procedures as efforts to tackle the root cause of global warming.
[...]
So far, most studies have modelled a “fully” geoengineered world in which CO2 concentrations are doubled compared with current or pre-industrial levels, and all the resulting warming is counterbalanced by a stratospheric sunshade. Instead, Peter Irvine of Harvard University and his colleagues simulated a partial sunshade. They were able to eliminate half the warming effect of doubled CO2 concentrations while stabilising the water cycle.
[...]
The researchers say their study is more relevant to real policy decisions because it shines some light on what could be done by, for instance, combining solar geoengineering with efforts to cut greenhouse gas emissions. But all this would require international consensus, and obtaining that may be a fantasy.
The barriers to unity were on display in Nairobi. In 2010 the Convention on Biological Diversity advised against geoengineering activities “until there is an adequate scientific basis” to justify them, but America is not a party to that convention. It was represented at unea. However, several delegates told this newspaper that America and Saudi Arabia opposed the Swiss proposal to review geoengineering, preferring the issue to be assessed by the Intergovernmental Panel on Climate Change (ipcc), which is due to include something about the technologies in its next big report, expected in 2021.
[...]
The only reason the world may need geoengineering is that talks about cutting emissions have gone on so long but achieved so little. Yet in Nairobi delegates could not even commission a report. Geoengineering, the toolbox that a decade ago nobody wanted, could end up stuck in the same international procedures as efforts to tackle the root cause of global warming.