Threats

Forests cover 31% of the land area on our planet. They produce vital oxygen and provide homes for people and wildlife. Many of the world’s most threatened and endangered animals live in forests, and 1.6 billion people rely on benefits forests offer, including food, fresh water, clothing, traditional medicine and shelter.

But forests around the world are under threat from deforestation. Deforestation comes in many forms, including fires, clear-cutting for agriculture, ranching and development, unsustainable logging for timber, and degradation due to climate change. This impacts people’s livelihoods and threatens a wide range of plant and animal species. Some 46-58 million square miles of forest are lost each year—equivalent to 36 football fields every minute.

Forests play a critical role in mitigating climate change because they act as a carbon sink—soaking up carbon dioxide that would otherwise be free in the atmosphere and contribute to ongoing changes in climate patterns. 

Deforestation is a particular concern in tropical rain forests because these forests are home to much of the world’s biodiversity. For example, in the Amazon around 17% of the forest has been lost in the last 50 years, mostly due to forest conversion for cattle ranching.

http://worldwildlife.org/threats/deforestation

Statistics

• In 1950, about 15% of the Earth's land surface was covered by rainforest. in fewer than 50 years more than half of the world's tropical rainforests have fallen due to fire and chainsaw. The destruction is increasing.
• Unbelievably, more than 200,000 acres of rainforest are burned every day. That is more than 150 acres lost every minute of every day, and 78 million acres lost every year.
• 20% of the Amazon Rainforest is gone.
• Its estimated that the Amazon alone is vanishing at a rate of 20,000 square miles a year!
  

CNN explains deforestation

Modern Day Plague

Deforestation is clearing Earth's forests on a massive scale, often resulting in damage to the quality of the land. Forests still cover about 30 percent of the world’s land area, but swaths the size of Panama are lost each and every year. Loggers, some of them acting illegally, also build roads to access more and more remote forests—which leads to further deforestation. Forests are also cut as a result of growing urban sprawl.

• Deforestation has many negative effects on the environment. The most dramatic impact is a loss of habitat for millions of species. Seventy percent of Earth’s land animals and plants live in forests, and many cannot survive the deforestation that destroys their homes. 
• Removing trees deprives the forest of portions of its canopy, which blocks the sun’s rays during the day and holds in heat at night. This disruption leads to more extreme temperatures swings that can be harmful to plants and animals.
• Trees also play a critical role in absorbing the greenhouse gases that fuel global warming. Fewer forests means larger amounts of greenhouse gases entering the atmosphere—and increased speed and severity of global warming.
• A more workable solution is to carefully manage forest resources by eliminating clear-cutting to make sure that forest environments remain intact.

"National Geographic Home Page." National Geographic. N.p., n.d. Web. 25 Nov. 2013.