According to Warren M. Washington, a scientist at the National Center for Atmospheric Research - which is funded by the National Science Foundation and the U.S. government, global warming is advancing inexorably and will indeed lead to more record temperatures, such as those experienced by many regions of the United States so far this year. Washington spoke at a lecture in May 2012 at the National Center for Atmospheric Research in New Mexico, in the seventh lecture given in a series.
Washington is an expert in atmospheric computer modeling and has served as presidential science adviser to five presidents, including Jimmy Carter, Ronald Reagan, Bill Clinton, George H.W. Bush and George W. Bush. He was awarded the National Medal of Science by President Obama in 2010.
Washington presented graph after graph showing how atmospheric processes have converged in creating greater levels of rainfall in the equatorial region, as well as more intense droughts in the subtropics. According to Washington, this has also led to rises in sea level and increased storm surges. Washington said more tropical diseases would move poleward as the tropics expand.
Washington said that there will be increased risks to national security as island and island and coastal countries disappear or are diminished because of rising sea levels. “Their populations will need to migrate elsewhere, causing immigration issues,” warned Washington. He advised, “People shouldn’t be building houses on the seacoast or putting houses in flood plains.”
Acknowledging those skeptical about climate change, Washington noted that Richard Muller of UC-Berkeley as a former skeptic of the belief that “we’ve warmed the planet by almost a degree [Celsius] from 1880 to 2010 in the global land temperature average.” Washington claimed that Muller and confreres used a different technique to compute Earth’s land temperature, but his graph only reproduced what others found earlier.
Challenging fellow scientists, Washington said “Climate skeptics often mention that solar radiation has changed and that is what is causing the climate change,” he while offering a graph charting the intensity of solar irradiance at the top of Earth’s atmosphere. “You can see 11-year cycles from 1975 on and you can see there is no significant trend on radiation coming into the atmosphere. So this argument by skeptics isn’t valid to the climate change community.”
Washington also said that extremes in temperature have grown since the 60s, He claimed that methane and nitrous oxide concentrations are increasing, ozone depletion is increasing. Concerning the melting of the polar ice caps, Washington said that the usually ice-blocked Northwest Passage in Canada should be open this fall for shipping if accompanied by an icebreaker. For Washington, 2010 was “a record year for glacier melting in Greenland, as observed by satellite.” Washington said glaciers are melting substantially around the globe. “Since the 1960s, ocean heat content, humidity, temperatures near just above the sea surfaces and the temperatures over land and oceans have increased substantially. Meanwhile, snow cover, glaciers and sea ice have decreased.”
As to causation, Washington said “Natural variations [used in models] do not explain climatic change. Climate model simulations with just natural ‘forcing,’ including volcanic and solar, do not reproduce warming. However, when the increase in greenhouse gases is included, models do reproduce the global warming patterns. We consider this a ‘smoking gun’ proof.” By factoring in the effects of aerosols to climate models, further agreement with the temperature-warming trends of the last decades is achieved, he said.
Washington said that slow computing had initially handicapped experiments to simulate climate change, while faster computing speeds have led to more accurate models.
However, said Washington, political meetings about climate change in Copenhagen, Cancun, and Durban, “haven’t gotten very far. Basically, there’s a lot of inertia in making big changes in our energy profile.” He theorized, “Many skeptics claim that climate change is a hoax and we have some sort of secret agenda to fool the public. Obviously, I believe there’s no conspiracy, that climate change is not a hoax and that the advice we give the policymakers is honest and good science.” Hazarding a guess at the reasons for climate skepticism, Washington said “We’re faced by a lot of people whose business interests are affected by climate change mitigation.”
His simulations showed that cutting back on carbon emissions and concentrations in the atmosphere would help curb future temperature rises. However, Washington said that geoengineering measures unlikely to do much. These include space mirrors to reflect light away from Earth and stratocumulus cloud seeding to brighten them so that more solar radiation is reflected out to space. The sequestration of carbon - storing it underground or on the ocean floor - shows more promise, he said. For the short-term, he mentioned the positive effect of reducing the amount of airborne methane and other non-greenhouse gases such as freon. “Climate system models are far from being perfect,” he said, “but are the best indicator of our science knowledge of how the climate system works.”