This op-ed originally appeared in the Washington Post.

Caution: It is vitally important not to make connections. When you see pictures of rubble like this week’s shots from Joplin, Mo., you should not wonder: Is this somehow related to the tornado outbreak three weeks ago in Tuscaloosa, Ala., or the enormous outbreak a couple of weeks before that (which, together, comprised the most active April for tornadoes in U.S. history). No, that doesn’t mean a thing.

It is far better to think of these as isolated, unpredictable, discrete events. It is not advisable to try to connect them in your mind with, say, the fires burning across Texas — fires that have burned more of America at this point this year than any wildfires have in previous years. Texas, and adjoining parts of Oklahoma and New Mexico, are drier than they’ve ever been — the drought is worse than that of the Dust Bowl. But do not wonder if they’re somehow connected.

Portland Metro Council President David Bragdon, says that mass migrations caused by climate change "the potential wild card" in the planning effort to ensure Oregon's biggest city has the capacity to accommodate growth expected in the coming decades.

Droughts, wildfires, hurricanes and tornadoes all present risks in other parts of the U.S. and Oregon, which already accepts 20,000 migrant Californians a year, is worried about what happens if that population suddenly explodes with large numbers of refugees from other parts of the country . 

The National Center for Atmospheric Research, an important hub for work on the causes and consequences of climate change, has shut down a program focused on strengthening poor countries’ ability to forecast and withstand droughts, floods and other climate-related hazards.

The move, which center officials say resulted from the shrinking of federal science budgets, is being denounced by many experts on environmental risk, who say such research is more crucial than ever in a world with rising populations exposed to climate threats.