Union of Concerned Scientists Letter

Here's an excerpt. If you're qualified, you can read the whole thing and sign it here.

U.S. Scientists and Economists’ Call for Swift and
Deep Cuts in Greenhouse Gas Emissions

We call on our nation’s leaders to swiftly establish and implement policies to brig about deep reductions in heat-trapping emissions. The strength of the science on climate change compels us to warn the nation about the growing risk of irreversible consequences as global average temperatures continue to increase over pre-industrial levels (i.e., prior to 1860).1,2 As temperatures rise further, the scope and severity of global warming impacts will continue to accelerate.

...The longer we wait, the harder and more costly it will be to limit climate change and to adapt to those impacts that will not be avoided. Many emissions reduction strategies can be adopted today that would save consumers and industry money while providing benefits for air quality, energy security, public health, balance of trade, and employment.5,6

...A strong U.S. commitment to reduce emissions is essential to drive international climate progress. Voluntary initiatives to date have proven insufficient. We urge U.S. policy makers to put our nation onto a path today to reduce emissions on the order of 80 percent below 2000 levels by 2050. The first step on this path should be reductions on the order of 15-20 percent below 2000 levels by 2020, which is achievable and consistent with sound economic policy. 5,6

There is no time to waste. The most risky thing we can do is nothing.

I note the publication includes the following statements by bona fide economists:

Preventing dangerous climate change is a great investment. It will cost between one and two percent of GDP, and the benefits will be between 10 and 20 percent. That’s a return of 10 to 1—attractive even to a venture capitalist.

Geoffrey Heal
Paul Garret Professor of Public Policy and Corporate Responsibility, Columbia
Business School, New York, NY; Co-organizer, U.S. Scientists and Economists’
Call for Swift and Deep Cuts in Greenhouse Gas Emissions

Cutting carbon—if done right—can spur the economy through energy savings and job growth.

Eban Goodstein
Professor of Economics, Lewis & Clark College, Portland, OR;
Director,
Focus the Nation

Since petroleum’s discovery in 1859, innovation has radically changed the structure and development of the world economy. Today, we must pursue innovation in clean energy, which offers similar long-term growth prospects. Delaying the necessary incentives and institutions to foster this transition will only narrow our choices and increase our costs.

Edward B. Barbier
John S. Bugas Professor of Economics, Department of Economics and Finance,
University of Wyoming

As emissions increase, any delays in action necessitate larger emissions cuts and higher
mitigation costs in the future.

Tom Teitenberg
Mitchell Family Professor of Economics, Colby College, Waterville, ME;
Former President, Association of Environmental and Resource Economists

So even in tenured economics professor terms there isn't a slam dunk here the way some people would have you think.