More Than 80 Scientists Endorse Joe Biden for President on the 50th Anniversary of Earth Day

April 21, 2020
The undersigned include Nobel Laureates; senior leaders in academia; lead authors of reports of the
Intergovernmental Panel on Climate Change (IPCC); public health experts; members of the National
Academies of Sciences, Engineering, and Medicine; and science advisors to multiple administrations of
both parties. We have made it our life’s work to advance the frontiers of scientific knowledge,
including informing society about the grave risks posed by climate change and other health and
environmental threats.
We are writing the week of the 50th Anniversary of Earth Day to endorse Joe Biden for President. Vice
President Biden has long trusted the scientific consensus on climate change and for more than thirty
years has advanced policies to support scientific research and slow climate change. As a U.S. senator, he
introduced one of the first climate change bills in 1986, promoted policies to curtail carbon emissions
as a Senator and through the Obama-Biden administration, and has committed to meet the climate
challenge with ambitious policies and urgent action as President. We are confident that, unlike
President Trump, Joe Biden will respect, collaborate with, and listen to leaders in the scientific
community and public health experts to confront the existential climate crisis and other
environmental threats.

Around the world, scientists overwhelmingly agree that greenhouse gas emissions are changing the
climate by warming global temperatures, raising sea levels, acidifying the oceans, and intensifying
droughts, wildfires, and severe storms. President Trump’s own administration released a national
climate assessment—with contributions from 300 scientists, including many of us—warning that
climate change could cost America hundreds of billions of dollars per year by the end of the century.
Regrettably, President Trump’s response to that report was: “I don’t believe it.” Worse, Trump has
repeatedly suppressed science and silenced scientists. His administration has scrubbed federal websites
of references to climate change and forced researchers to truncate forecasts from scientific models
investigating the dire consequences of climate change. He has barred widely respected scientists from
sitting on the Environmental Protection Agency’s scientific advisory board; sought to block the use of
relevant scientific research in making federal regulations; and even defunded critical research about
how high levels of pollution impact the healthy development of children.
We believe it is our solemn responsibility to inform our fellow citizens about the dangers of climate
change and about the actionable pathways to slow it. But time is running out: global emissions must
fall sharply by 2030 and swiftly reach a net-zero level thereafter to avert a climate catastrophe. Without
leadership, strong policy, global cooperation, and technological innovation, the world will not be able
to rein in runaway greenhouse gas emissions in time. Vice President Biden’s plan to address climate
change leads with science and facts and pledges U.S. leadership on climate action. By contrast,

 President Trump abandoned the Paris Climate Agreement abroad and has refused to follow the
science as he dismantles nearly one hundred environmental rules and regulations at home.
Now more than ever, the United States needs a President who trusts and respects scientists and will
confront the climate crisis head on, rather than leave our children and grandchildren to suffer its
consequences. On Earth Day, we speak with one voice: we must elect Joe Biden the next president of
the United States—for all our sakes.

The below experts are co-signing in their personal capacity and not on behalf of institutions or
organizations with which they may be professionally affiliated.
Signed,
Andreas Acrivos, Ph.D.
Bruce Alberts, Ph.D.
Bernard Amadei, Ph.D.
John Balmes, M.D.
Bonnie. L. Bassler, Ph.D.
James M. Berger, Ph.D.
Indy Burke, Ph. D.
Donald D. Brown, M.D.
John Carlson, Ph.D.
Christine K. Cassel, M.D.
Kim Cobb, Ph.D.
Dan Costa, Ph.D.
Yi Cui, Ph.D.
John O. Dabiri, Ph.D.
Gretchen C. Daily, Ph.D.
Ruth DeFries, Ph.D.
Pete DeMenocal, Ph.D.
Abby F. Dernburg, Ph.D.
Tammy Dickinson, Ph.D.
David Drubin, Ph.D.
Andrea Dutton, Ph.D.
Anne Ehrlich
Paul R. Ehrlich, Ph.D.
Michael B. Eisen, Ph.D.
L. W. Enquist, Ph.D.
Steve Fetter, Ph.D.
Linda Fried, M.D.
Joseph Gall, Ph.D.

 Lisa Goddard, Ph.D.
Carol W. Greider, Ph.D.
Taekjip Ha, Ph.D.
Zeke Hausfather, Ph.D.
John Holdren, Ph.D.
Kathy Jacobs, M.L.A.
Richard J. Jackson, M.D./M.P.H.
Jon Jarvis
Daniel Kammen, Ph.D.
Patrick L. Kinney, Ph.D.
Bob Kopp, Ph.D.
Se-Jin Lee, M.D./Ph.D.
Arthur L. Lerner-Lam, Ph.D.
Michael Lu, M.D./M.S./M.P.H.
Jane Lubchenco, Ph.D.
Amy Luers, Ph.D.
Katharine Mach, Ph.D.
Arunava Majumdar, Ph.D.
Michael E. Mann, Ph.D.
Barbara Meyer, Ph.D.
Jerry L. Miller, Ph.D.
Joshua W. Modell, Ph.D.
Jeremy Nathans, M.D./Ph.D.
Franklin M. Orr, Jr., Ph.D.
A.-H. Alissa Park, Ph.D.
Gregory A. Petsko, D.Phil.
William H. Press, Ph.D.
Sonny Ramaswamy, Ph.D
Irwin Redlener, M.D.
Jasper Rine, Ph.D.
Donald Rio, Ph.D.
Andrew A. Rosenberg, Ph.D
Linda Rudolph, M.D/M.P.H
Barbara Schaal, Ph.D.
Randy Schekman, Ph.D
Jeffrey Shaman, Ph.D.
Drew T. Shindell, Ph.D.
Thomas J. Silhavy, Ph.D.
Bob Simon, Ph.D.
Varun Sivaram, Ph.D.
Jason E. Smerdon, Ph.D.

 Kirk Smith, Ph.D
Adam H. Sobel, Ph.D.
Sean Solomon, Ph.D.
Alfred Sommer, M.D.
Richard W. (Rick) Spinrad, Ph.D.
Dan Steingart, Ph.D.
Susan Strome, Ph.D.
Karel Svoboda, Ph.D.
Fyodor D. Urnov, Ph.D.
Harold Varmus, M.D.
Adm. Jon White (Ret.)
Robert H. Wurtz, Ph.D.
King-Wai Yau, Ph.D.