In a recent Scientific American interview, renowned physicist David Deutsch answered a question thusly:
SA: “Do you think concerns about climate change and other environmental problems are excessive?”
Deutsch: “Resource-depletion and overpopulation worries are fundamentally flawed. Climate change worries are fundamentally misdirected. Geoengineering is essential, unavoidable and is being downplayed and delayed because of the ‘moral hazard’ that people will be distracted from reducing carbon dioxide emissions. The latter should be the third most important response, after geoengineering and mitigation of the effects of climate (changed and otherwise) on people.”
This is precisely what I believe. The climate is changing, and for the worse from a human perspective. Most of those who deny this do so because they find the consequences of facing reality distasteful. Others are simply scientifically illiterate. There is a somewhat legitimate argument surrounding the degree to which human activity is the driving force for these changes. But that is largely irrelevant to the main point, which is that the most promising and accessible responses have somehow been hijacked by this quixotic attempt to cure the problem simply by reducing carbon emissions. Not that this wouldn’t be helpful, but it is unlikely to be effective for both technical and political reasons. Moreover it diverts attention and resources from more promising solutions. I think this is mostly a consequence of well-meaning amateurs attempting to set scientific policy.
So, by all means let’s stop making it worse by spewing more greenhouse gases into the atmosphere. But don’t lose sight of our real goal in the process. We must accept the most likely future, even with our best efforts, and stop pretending that we can somehow halt the consequences of an industrial revolution that has otherwise brought enormous benefits to the human race. It is too late for such wishful thinking.
Geophysical changes have enormous inertia. There are estimates that even if we instantly reverted to a pre-industrial world, the climate would inexorably become more threatening before it finally recovered. Some effects are self-propagating. Glacial melt and warming of the vast northern tundra are prime examples. Methane is a far more potent greenhouse gas than carbon dioxide, and the ocean basin and continental tundra are emitting this in steadily increasing quantities.
We are at the cusp of real progress in geoengineering and that is where real hope resides. At the same time we must urgently invest vastly greater effort in protecting our resources and population from the most likely outcome.
Keep in mind that commercial interests have caused us to cluster on continental fringes world-wide. Many of our great cities lie beside oceans that will rise and be more turbulent as they grow warmer. They are at great risk. It will take a long time and enormous expense to protect or relocate critical infrastructure. Time is of the essence.