More than 120 House members today will reintroduce the Safe Climate Act, which offers the best opportunity to protect future generations from the worst effects of global warming, according to the Union of Concerned Scientists (UCS). The bipartisan bill, spearheaded by Henry Waxman (D-Calif.), calls for an 80 percent reduction of global warming pollution from 1990 levels by 2050, a cut that UCS scientists say is necessary to avoid the worst consequences of climate change.

“The Safe Climate Act's reduction targets match the magnitude and urgency of the global warming threat,” said Alden Meyer, director of strategy and policy at UCS. “This bill will help secure a healthy world for our children and grandchildren.”

Global warming already is causing more severe storms, heat waves, droughts and speeding up the spread of water- and pest-borne diseases. Considerable scientific evidence indicates that an additional warming of 2 degrees Fahrenheit or more above today's levels would greatly exacerbate these and other dangerous threats to public health and the environment. Sustained warming above this level also poses the risk of large-scale, irreversible changes, including the extinction of many species and a sea level rise of as much as 20 feet resulting from the destruction of the Greenland and West Antarctic ice sheets. 

Alternatively, if the nations of the world cut global warming pollution sufficiently to prevent concentrations of heat-trapping gases from exceeding 450 parts per million (ppm CO2 equivalent), we may be able to keep further global average temperature increases below 2 degrees F and avoid the most damaging effects of global warming.

Staying under the 450 ppm threshold would require cutting global emissions roughly in half from today's levels by mid-century. Given that the United States leads the world in both absolute and per capita emissions, Americans must achieve even deeper reductions.

Because heat-trapping emissions remain in the atmosphere for hundreds of years, the world is facing an increase of more than 1 degree F no matter what policies are enacted. In other words, the globe is nearly half way to the threshold beyond which we could see the worst effects of climate change. That's why the  federal government must act soon to achieve serious reductions in global warming emissions across all sectors of the economy.

Congress currently is considering several climate change bills that call for varying levels of emissions reductions, but according to UCS experts the Safe Climate Act and the Senate's Global Warming Pollution Reduction Act – whose primary sponsors are Barbara Boxer (D-Calif.) and Bernie Sanders (I-Vt.) – provide the best chance of staying below a 2 degrees F temperature increase above today's levels. Both bills require a gradual but deep reduction of U.S. global warming emissions to 80 percent below 1990 levels by 2050.

The Safe Climate Act would freeze global warming emissions at 2009 levels in 2010, and then reduce them by approximately 2 percent per year from 2011 to 2020. These cuts could be achieved using existing renewable energy, energy efficiency, and clean vehicles technologies, according to UCS. After 2020, the bill would require emissions cuts of about 5 percent annually, as more advanced technologies become widely available.

To help achieve these reductions, the Waxman bill requires energy efficiency improvements, increased reliance on renewable energy, and cleaner cars.  The bill also provides flexibility to help companies meet the pollution-reduction goals through a "cap-and-trade" program. 

In addition to protecting future generations from the worst effects of global warming, these policies also would help to reduce U.S. dependence on oil, improve air quality, and protect pristine places from oil drilling.