The Wall Street Journal published a letter expressing skepticism about anthropogenic climate change signed by a group of engineers, retired weathermen, and scientists from fields other than climate science.
In response, a much larger group of actual climate scientists signed onto a letter rebutting the first letter. The WSJ rejected it. Instead, the pre-eminent science journal Science, which is know for its rigor in treatments of science, published it, as "Climate change and the Integrity of Science" on January 27th, 2012.
(i) The planet is warming due to increased concentrations of heat-trapping gases in our atmosphere. A snowy winter in Washington does not alter this fact.
(ii) Most of the increase in the concentration of these gases over the last century is due to human activities, especially the burning of fossil fuels and deforestation.
(iii) Natural causes always play a role in changing Earth's climate, but are now being overwhelmed by human-induced changes.
(iv) Warming the planet will cause many other climatic patterns to change at speeds unprecedented in modern times, including increasing rates of sea-level rise and alterations in the hydrologic cycle. Rising concentrations of carbon dioxide are making the oceans more acidic.
(v) The combination of these complex climate changes threatens coastal communities and cities, our food and water supplies, marine and freshwater ecosystems, forests, high mountain environments, and far more.