Brazilian President Dilma Rousseff said the emissions reduction target would reduce the largest economy in Latin America's emissions by 37 percent by 2025 compared to 2005 levels. Brazil also set the target to reduce emissions by 43 percent by 2030.
The pledge came at a UN summit establishing new development goals, which include talks on a climate change agreement set to be negotiated in Paris in December.
Rousseff said Brazil would reach the emissions reduction target through a combination of increasing renewable energy to 45 percent of energy use, stopping illegal deforestation by 2030 and restoring or replanting large swaths of the Amazon rainforest and pasture.
Looking toward Paris climate summit
The announcement comes as world leaders will convene in Paris in December in an effort to reach a binding agreement to reduce greenhouse gas emissions causing global climate change.
Previous attempts to strike a deal have failed over differences between developed and developing countries - particularly the US and China - the two largest greenhouse gas emitters in the world.
However, the US and China struck a deal last year after months of negotiations. Under the agreement, the US pledged to cut greenhouse gas emissions between 26 and 28 percent from 2005 levels by 2025. China pledged to peak emissions by 2030.
Brazil - another key greenhouse gas emitter and a country with massive forests that help to act as the lungs of the Earth - now also comes into the Paris talks with a fresh commitment.
In August, German Chancellor Angela Merkel visited Brazil, where she committed 550 million euros ($615.78 million) to help finance environmental projects. Some 525 million euros ($587.79 million) of that financing is slated for renewable energy and forest preservation.
cw/gsw (AP, AFP, dpa, Reuters)