A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems. – U.S. National Academy of Sciences, 2010This January 2011 NASA chart shows 2010 tied (with 2005) for the hottest year on record, and is part of the hottest decade on record. It "is compiled from weather data from more than 1000 meteorological stations around the world, satellite observations of sea surface temperature and Antarctic research station measurements."
Multiple reconstructions of historic temperatures show it is now the hottest in 2,000 years (PDF). More perspective on temperature reconstructions from Climate Progress and Skeptical Science.
Glaciers and ice sheets are melting around the world. For example, Muir Glacier in Alaska's Glacier Bay National Park, 1892 (left), has vanished in 2005 (right; both USGS).
Arctic sea ice is at record lows, and melting of the Greenland and Antarctic ice sheets is increasing. The “Albedo Effect” of shiny ice replaced by dark ocean further accelerates warming.
Not only is sea level rising, but most of the excess heat and has been absorbed in the ocean, resulting in stronger hurricanes. CO2 is also making the ocean more acidic, endangering shellfish and coral reefs.
A new NASA-Jet Propulsion Laboratory study projects a one-foot rise by 2050. If the 100,000-year-old, mile-thick Greenland Ice Sheet melted it would raise sea level over 23 feet.
Effects of global warming include extreme weather – severe heat, storms, floods, drought and dust bowls. Great wildfires (photo – Station Fire behind downtown Los Angeles, August 2009) are a result of heat, drought, and pine borer beetles that were formerly killed by cold winters.
Greater heat and less water reduce food crops.
Climate doesn't change all by itself for no good reason. Something has to force it. – Mark Serreze, National Snow and Ice Data Center director
The Greenhouse Effect is well-documented. That something is CO2 levels, primarily from burning fossil fuels over the last century – and other greenhouse gases – that have risen with temperature (NASA chart). This atmospheric CO2 acts like a thermostat to control the temperature of the Earth.
Warming is not caused by the sun: temperature is rising despite falling solar irradiance.
In fact, 97% of climate experts agree humans are causing global warming via greenhouse gas emissions.
See more in NASA's Climate change: How do we know?, Empirical evidence that humans are causing global warming, and Climate Progress, especially:
- An illustrated guide to the latest climate science
- An introduction to global warming impacts: Hell and High Water
- A stunning year in climate science reveals that human civilization is on the precipice
Transportation is the second-largest emissions sector nationally (above, US EPA, Tables 2-12 & 2-15) and the greatest in California (due to less coal-fired electricity, below, CARB; more on AB 32 Scoping Plan)
NEXT: 3. Alternatives to Driving BACK: 1. Oil Supply