Has Anybody Pointed Out

Conservatives continue to insist that the observed warming of the Earth has a natural rather than a human cause. To judge from the tendency of articles I’ve read in various journals, the consensus against this proposition is pretty strong and getting stronger—the most recent issue of SCIENCE included a paper reporting evidence that the troposphere, the lowest level of the atmosphere, is swelling, a phenomenon consistent with anthropogenic warming—but the issue of why the Earth is warming may be less important than the more imperious fact that it is warming. Mankind may have to take collective action to deal with the consequences of global warming whatever its cause. And even if, contrary to the current evidence, greenhouse gases aren’t responsible for the warming the Earth, reducing emissions of such gases would remain an obvious way to counter a rise in average temperatures.