In the Amazon jungle's sweltering heat, Brazilian Indians and officials joined together to urge U.N. Secretary General Ban Ki-moon to garner international support in protecting the world's largest rainforest. Brazilian Environment Minister Marina Silva emphasized the need for tangible mechanisms to benefit the Amazon's residents, speaking to Ban under a century-old Samauma tree near Belem, the region's largest city. This plea came as Ban concluded a South American tour focused on the effects of global warming, which included a recent visit to Antarctica. Amazon Indian Marcos Apurina also implored Ban to assist in creating opportunities for forest dwellers to sustain themselves in the region. Ban, who explored a jungle trail on Combu island in the Guama River, pledged the United Nations' support for their cause. This is a shared asset of all people on Earth." Before, Ban interacted with a three-toed sloth and planted two native trees at a botanical garden in Belem. Ban is getting ready for a UN climate change conference in Bali, Indonesia, in December, where discussions to limit carbon emissions after the Kyoto Protocol ends in 2012 will begin. Brazil is responsible for the world's fourth-largest amount of carbon emissions, largely because of the Amazon rainforest's destruction, as reported by international environmental organizations. Ban did not address Brazil's decision not to set goals to decrease deforestation and carbon emissions. Instead of criticizing Brazil, he praised the country for its efforts in reducing forest destruction by 50% in two years, even though the rate has increased again recently. The Amazon contributes to global warming by releasing carbon dioxide when trees are burned or decompose. Farmers and loggers continue to clear large areas of the forest each year, depending on the prices of grain, beef, and timber. Silva, a former rubber tapper and activist, asked Ban to support a proposal within the international Convention on Biodiversity that would require pharmaceutical companies to pay for drugs derived from Amazon medicinal plants, despite opposition from some Western countries. Ban agreed to study the proposal after a meeting with Silva on Monday. Scientists warn that global warming may transform a section of the Amazon into semi-arid savanna in the coming decades. Severe weather patterns have led to droughts in some areas and floods in others. Secretary-General Ban's scheduled trip along an Amazon tributary near Santarem had to be called off due to shallow waters. Ban commended Brazil for its efforts in developing low-emission biofuels but stressed the need for further international research to assess the potential impact of large-scale production on food supplies. Over the weekend, he visited a plant in Sao Paulo state, where Brazil is known for being one of the largest and most cost-effective producers of ethanol. President Luiz Inacio Lula da Silva's administration has escalated law enforcement actions against illegal loggers and enlarged protected territories. However, there is concern among conservationists that the construction of roads and hydroelectric facilities could potentially lead to an increase in deforestation over time.