A Swedish award widely described as the "alternative Nobel prize" has gone to activists from the Democratic Republic of Congo, Australia and New Zealand.
Rene Ngongo, of Greenpeace, was one of the recipients of the annual "Right Livelihood Award" for his efforts to protect the Congolese rain forest.
Catherine Hamlin, an Australian doctor who lives in Ethiopia, was honoured for her medical research benefiting women.
New Zealander Alyn Ware was recognised for efforts on nuclear disarmament.
Each will also receive 50,000 euros ($74,000) from the Right Livelihood Award Foundation.
The foundation was set up by Swedish-German philanthropist Jakob von Uexkull in 1980 "to honour and support those offering practical and exemplary answers to the most urgent challenges facing us today".
The recipients demonstrate concretely what has to be done in order to tackle climate change, rid the world of nuclear weapons, and provide crucial medical treatment to the poor and marginalised
Right Livelihood Award Foundation
An honorary award, which does not include any prize money, was given to the Canadian environmentalist and television presenter David Suzuki for raising awareness of climate change.
"Despite the scientific warnings about the imminent threat and disastrous impacts of climate change and despite our knowledge about solutions, the global response to this crisis is still painfully slow and largely inadequate," the Right Livelihood Award Jury said.
"At the same time, the threat from nuclear weapons has by no means diminished, and the treatable diseases of poverty shame our common humanity," it added.
"The 2009 Right Livelihood Award Recipients demonstrate concretely what has to be done in order to tackle climate change, rid the world of nuclear weapons, and provide crucial medical treatment to the poor and marginalised."