Avoiding catastrophic global warming requires stabilizing carbon dioxide concentrations, not emissions. Studies find that many, if not most, people are confused about this, including highly educated graduate students. I have personally found even well informed people are confused on this point and its crucial implications:
We need to cut emissions 50% to 80% below current levels just to stop concentrations from rising. And global temperatures will not be stabilized for decades after concentrations are stabilized. And of course the ice sheets may not stop disintegrating for decades — and if we dawdle too long, centuries — after temperatures stabilize. That is why we must act now if we want to have any reasonable hope of averting catastrophe.
One 2007 M.I.T. study, “Understanding Public Complacency About Climate Change: Adults’ mental models of climate change violate conservation of matter,” concluded “Low public support for mitigation policies may be based more on misconceptions of climate dynamics than high discount rates or uncertainty about the risks of harmful climate change.”
Here is a great video clarifying the issue, which you can send to folks. It is narrated by my friend Andrew Jones. If you want to play the simulation itself, go here. They make use of the bathtub analogy: While atmospheric concentrations (the total stock of CO2 already in the air) might be thought of as the water level in the bathtub, emissions (the yearly new flow into the air) are the rate of water flowing into a bathtub.
As Sterman writes, “So the SOTU still reflects deliberate and careful use of language to make delay sound like action.”
I recommend reading the entire MIT study, whose lead author is John Sterman. Here is the abstract:
Public attitudes about climate change reveal a contradiction. Surveys show most Americans believe climate change poses serious risks but also that reductions in greenhouse gas (GHG) emissions sufficient to stabilize atmospheric GHG concentrations or net radiative forcing can be deferred until there is greater evidence that climate change is harmful. US policymakers likewise argue it is prudent to wait and see whether climate change will cause substantial economic harm before undertaking policies to reduce emissions. Such wait-and-see policies erroneously presume climate change can be reversed quickly should harm become evident, underestimating substantial delays in the climate’s response to anthropogenic forcing. We report experiments with highly educated adults–graduate students at MIT–showing widespread misunderstanding of the fundamental stock and flow relationships, including mass balance principles, that lead to long response delays. GHG emissions are now about twice the rate of GHG removal from the atmosphere. GHG concentrations will therefore continue to rise even if emissions fall, stabilizing only when emissions equal removal. In contrast, results show most subjects believe atmospheric GHG concentrations can be stabilized while emissions into the atmosphere continuously exceed the removal of GHGs from it. These beliefs-analogous to arguing a bathtub filled faster than it drains will never overflow-support wait-and-see policies but violate conservation of matter. Low public support for mitigation policies may be based more on misconceptions of climate dynamics than high discount rates or uncertainty about the risks of harmful climate change.