First of all climate change impact would be much stronger because forests and rainforests absorb large quantities of CO2 (carbon dioxide). CO2 is harmful greenhouse gas mostly responsible for global warming and climate change, and without rainforests lot more of this gas would end up in the atmosphere causing even bigger global warming impact. So as you can see forests are one of nature's defense systems against climate change problem. This is arguably their most important role but definitely not the only role they know how to play.
Forests also have tremendous impact on climate itself by regulating temperature, they produce several important nutritients like nitrogen and phosphor. Rainforests are also the areas of richest biodiversity on our planet with thousands of endemic animals and plants that are unique to them. There are many scientists that believe how rainforests could be also hiding cures for currently incurable diseases (Aids) because of thousands of plants that are still undiscovered. Some estimates even say that we are losing 137 plant species every single day due to rainforest deforestation. One of this plant species could easily be cure for some nasty disease but sadly we will never know was it or not.
Tropical rainforests are home to many unique plants. One of these plants could perhaps turn out to be cure for aids or some other currently incurable diseases.
Just imagine these tropical rainforests that stood for millions of years are being cleared each day by chainsaws, bulldozers and fires. We are destroying in a blink of an eye something that was created for many millions of years. How big is deforestation in Amazon? In the last 40 years Brazil (60 % of total Amazon rainforest) lost more than 600,000 sq km (232 000 sq miles) of Amazon rainforest, and the worst deforestation years were between 1991 and 2000 when the total area of forest lost in the Amazon rose from 415,000 to 587,000 km2
Why is Amazon rainforests being so heavily destroyed? Main cause for Amazon rainforest deforestation is definitely clearing forest area for cattle pasture. This most important reason of deforestation in Amazon rainforest caused deforestation of seventy percent of formerly forested land in the Amazon, and 91% of land deforested since 1970, is used for cattle pasture. Human population is constantly growing, needing more and more food, and this is where big profits play their role. Cattle breeding is traditional business in Brazil that gives nice profits (especially since meat prices are constantly rising), and what is equally important it doesn't require big maintenance expenditures. What it requires though is large area, and Amazon rainforest is the one that stands in the way of high profit. As in many other cases too, environment and ecology are much less important than economy and high profits and rainforests are being cleared out. Cleaning forest area for cattle pasture causes somewhere around 60-70 % of total deforestation, and is by far the biggest cause for tremendous deforestation in Amazon rainforest. Areas, once full of trees are now savannas and other coarse grasses needed for cattle pasture.
When Amazon rainforests isn't making room for savannas and cattle, it is making room for new farms. Population in Brazil and other South American countries is constantly increasing, and since we are talking here about traditional countries mostly oriented on agriculture it is no surprise that large areas of forests are being cleared to make rooms for new farms. Poverty is still very much present in Brazil and government in many cases stimulates poor population to settle in these areas by creating new farms. Farmers mostly use fire for clearing forests, and this is the most negative thing in whole deforestation story. Not only does this mean that large areas of forests are being destroyed, this also means that many CO2 gets released in atmosphere giving more impact to climate change. According to scientists deforestation is second most important cause for global warming phenomenon, responsible for more than 20 % of total CO2 emissions.
Farms are in most cases soybean farms, especially after biofuels were discovered. Of course profits are once again very high, in fact profits are so high that Brazil has more than remarkable growth in soybean production, so big that is only matter of day before Brazil becomes No. 1 soybean producer, and overtakes U.S. as the main producer. Farms are responsible for about 20 % of total Amazon rainforest deforestation but this percentage is steadily growing in last couple of years driven by higher food prices and bigger profits.
Next cause for excessive Amazon rainforest deforestation is logging. People often mistake logging as the biggest cause of deforestation but this is far from truth. In reality logging is causing only 3-4 % of total deforestation. However even this percentage, though it seems small, it is still not negligible. Tropical rainforests are excellent sources of many quality and expensive wood (ebony), and this is the reason why many people turn to illegal logging as highly profitable business. Illegal logging is still big problem in Brazil, and there is still not adequate control that would put an end to a steady rise in illegal logging. Brazilian government still fails to take serious actions against illegal loggers, and the longer the government delays serious action the more Amazon rainforest gets cleared.
Another reason responsible for destruction of Amazon rainforest is infrastructure building, responsible for about 3 % of total Amazon rainforest deforestation. The main problem with infrastructure building in Amazon is lack of sustainable management and good planning. The best example for this was building of infamous Trans-Amazonian Highway. Trans-Amazonian Highway had its purpose in not only connecting far places of the land, but also to open new areas for farms and easier exploit of quality woods. After this project was finished lack of sustainable management showed its full face, and deforestation took unprecedented level because now with available roads lot more forest areas become available for clearance.
When all this deforestation factors are summed up, the estimates say that the current rate of Amazon rainforest is so big that in two decades from now the Amazon rainforest will be reduced by 40%. If this is about to happen then this would probably be one of the biggest environmental disasters in history of our planet if not the biggest one. So we definitely need to prevent this from happening. But how to do this?
First of all rich countries should step in and ensure huge funds to stop deforestation. This money should be given to poor people that live in Amazon so they wouldn't need so many farms, and so many cattle to survive. Of course it is not enough to just collect money for this it is also important to make it sure that this money gets to the right people and not to end up in the pocket of some corrupted politician.
Another thing that should be definitely done is rehabilitation of formerly forested areas that are not longer interested to farmers. If only one small part of former ecosystem is saved this should be enough to start the rehabilitation. Also government needs to ensure more protected areas in Amazon rainforest. However in order for all of this to work farmers should really be more ecologically educated so they could understand the true importance of tropical rainforests. There are of course the laws. The laws are currently nor strict enough nor precise enough to stop the deforestation. Laws against deforestation need serious sentences to their offenders (jail sentences instead of fines), and government has to promote the importance of rainforests where ever and when ever possible. Unless people learn the importance of rainforests, profits will be always more important than Amazon rainforest. Money is not everything, and people have to realize this as soon as possible. Otherwise, not only survival of Amazon rainforest will be at stake but our own survival too.