The Grantham Foundation for the Protection of the Environment (TGF) provides funding for environmental organizations. TGF is funded by Jeremy Grantham his wife Hannelore and is based in Boston, Massachusetts.
Jeremy Grantham is a British investment manager known for funding a number of environmentalist organizations.  The Jeremy and Hannelore Grantham Environmental Trust is a subordinate organization of the Grantham Foundation.
The Grantham Foundation and people associated with the Grantham network of environmentalist groups have expressed open hostility to the market economy.
Jeremy Grantham, the principal funder of the Grantham Foundation, is a supporter of population control, having suggested the critical population limit of the earth at 10 billion.  In an interview with the Financial Times, Grantham compared himself to the nineteenth century economist Thomas Malthus by stating, “X marks spot where Malthus wrote his defining work. Y marks my entry into the world. What a surge in population has occurred since then! Such compound growth cannot continue with finite resources.” 
Grantham has stated that perhaps Karl Marx and Friedrich Engels were correct in their analysis of capitalism saying, “globalization would offer capitalists more rope to hang themselves with rope bought from briskly competing capitalists, eager till the end for a good deal.” Grantham continued that the “loss of collective ability to feed ourselves, through erosion and fertilizer depletion – has received little or no attention.” 
In 2012, Grantham said that to “interfere with Marx’s apocalyptic vision [of capitalist collapse], we need some enlighted governmental moderation…before capitalism gets so cocky that we have some serious social reaction.” 
In 2013, Grantham told The Guardian of the People’s Republic of China: “to hell with their five-year plans, they should move up to 25-year plans. They would have such low-cost energy at the end of it they’d be the terror of the capitalist system.” 
In 2019, Mr. Grantham stated that “I have a very low opinion of capitalism in 2019. We have reached a new low.” “Basically, the capitalist beast is out of control, and it doesn’t owe any responsibility to the society it lives in, the town, the state or country even.” 
Grantham has also stated, “On income inequality, I am left of Karl Marx.” 
Howard Stern, who chairs the Grantham Research Institute on Climate Change and Environment, has said without a rapid transformation of the global economy, the world faces economic decline. 
Jeremy Grantham is the principal funder of the Grantham Foundation alongside his wife Hannelore. Grantham is best known for predicting markets corrections bubbles over the years and also the funding of major environmental groups across the world. 
TGF is funded almost entirely by Jeremy and Hannelore Grantham through personal contributions. The Granthams have promised to contribute 98 percent of their net worth, or about $1 billion, to fight global warming and overpopulation concerns.
TGF has provided grants to the Acadia Center, American Association for the Advancement of Science, Azuero Earth Project, the Carbon Tracker Initiative, Center for Public Integrity, Climate and Health Research, Climate Foundation, CO2 Sciences, Community Foundation of Southeastern Massachusetts, Conservation Law Foundation, Conservation X Labs, Divecha Centre for Climate Change, Earth Innovation Institute, Environmental Defense Fund, Environmental League of Massachusetts, Greenpeace Fund, Health in Harmony, Linden Trust for Conservation, Lost Light Projects, Metafoundation, New England Forestry Foundation, Oxfam America, Rainforest Action Network, Rethinking Economics, Rockefeller Family Fund, Rocky Mountain Institute, Sierra Club, South Carolina Coastal Conservation, Stichting European Climate Foundation, Sustainability Accounting Standards Board, the Energy Foundation, Union of Concerned Scientists, WGBH Education Foundation, WILD AID, Woods Hole Research Center, and the World Resources Institute. 
TGF also supports the Grantham Research Institute on Climate Change and the Environment at the London School of Economics, and the Grantham Centre for Sustainable Futures at the University of Sheffield.