The heat wave

Political maneuvering and science are at odds in the debate about global warming, with extreme positions that blame polluting gases for recent weather events or exempt them from all responsibility. The reality, apparently, is somewhere in the middle.

Extreme weather phenomena, such as severe draughts and heat waves, have natural origins. But the impact of the environmental pollution produced by human activity elevates these phenomena to extraordinary conditions that break new temperature records.

That is the conclusion of the annual “State of the Climate” report published jointly by the National Oceanic and Atmospheric Administration (NOAA) and the United Kingdom’s Met Office. These are two scientific agencies that cannot be accused of environmental extremism, a label used by conservative groups that reject the idea of a relationship between polluting gas emissions and global warming.

Scientists documented the fact that greenhouse gas concentrations continued increasing last year and that the global average atmospheric concentration for carbon dioxide exceeded 390 parts per million for the first time, an increase of 2.1 ppm compared with 2010.

Also, scientists say that perhaps 90% of a heat wave is natural, but the additional 10% that increases the temperature to record numbers is influenced by polluting emissions.

For example, NOAA’s statistics show that the highest temperatures in the U.S.-since records have been kept-occurred in the past 12 months, and that the first six months of 2012 were the hottest such period on record, with more than 170 high-temperature records matched or broken.

This information should bring opposing political positions about global warming closer to each other-including those who from an environmental position want to impose strict emissions-control measures and those who refuse them, mainly because of the negative economic impact those controls have on the private sector.

In reality, doing nothing also has a high cost: losses and damages connected to extreme meteorological phenomena.

It will be hard for this change to happen given the polarized environment in Congress, where for ideological reasons-such as opposing regulation-scientific facts are rejected. Unfortunately, on this issue as on several others, the strategy to tackle the problem is in the hands of voters rather than up to scientists or politicians.