Earth system models suggest significant weakening, even potential reversal, of the ocean and land carbon sinks under future negative emission scenarios. Weakening of natural carbon sinks will hinder the effectiveness of negative emissions technologies and therefore increase their required deployment to achieve a given climate stabilisation target.
In recent years, international trade has displaced radiative forcing related to aerosols such as black carbon, sulfate, nitrate and ammonium from developed, net-importing nations like the U.S. to emerging, net-exporting nations like China. We quantify this shift and discuss its policy implications.
Existing technologies, institutions, and behavioral norms together constrain the rate and magnitude of carbon emissions reductions in the coming decades. We review recent research on "carbon lock-in," the implications for decarbonization efforts, and propose a research agenda that can help bridge the gaps between science, knowledge and policy-making.
76 of the 77 (98.7%) scientists we surveyed had not encountered evidence of a secret, large-scale atmospheric spraying program, and said that purported evidence are more easily explained by well-understood physics and chemistry associated with aircraft contrails and atmospheric aerosols.
The benefits and costs of CO2 emissions are commonly dislocated across space, time, and organizational level. When beneficiaries have greater political influence than those impacted, the result will be tragically suboptimal. Appeals to conscience and the responsibility of beneficiaries will not solve the problem; so long as interests are dislocated, use of fossil energy must be curtailed by effective policy
Most scenarios that avoid 2°C of global warming require large-scale deployment of negative emissions technologies. We review the impacts and resource demands of such deployment, and conclude that it's cheaper, easier and less risky to tackle global warming before fossil CO2 is in the atmosphere.