Global warming fatal to trees
forests are breathtaking. In fact, trees are effectively the greatest CO2 warehouses to have ever evolved on Earth. For every metric ton of wood created, 1.5 metric tons of CO2 is absorbed and 1 metric ton of oxygen is released.
Frighteningly, Earth’s forests are dying from a warming world.
Recently researchers once again sent an SOS call to denizens of Earth — drought conditions are placing deadly waterstress on forests around the globe. Moreover, Earth’s forests and myriad “ecosystem services” that provide all life are approaching an irreversible tipping point.
In 2009 the International Union of Forest Research Organizations came to a very bleak conclusion: “The carbon storing capacity of Earth’s forests could be lost entirely if the planet heats up 4.5 F above pre-industrial levels.” So far, we have increased by about 2 F, which means we are already well on our way toward this fateful threshold. The result of crossing it would be an uninhabitable world.
Rising greenhouse gases are also wreaking havoc in the tropical forests, more specifically in the Amazon. The heart of the Amazon has not evolved to contend with fierce winds, nor with drought. In 2005 a vicious combination of climate disruption occurred across a 733,600 square miles of land. In January, an intense thunderstorm, spanning 62 by 124 miles, ripped through the whole Amazon Basin. On its path, the storm leveled between 441 million and 663 million trees — or the equivalent of 23 percent of the estimated mean annual carbon accumulation capacity of the Amazon forest.
Later in 2005 a “one-in-100 year” drought occurred. Not only did the Amazon fail to absorb 1.5 billion metric tons of CO2 that year, but also over the next decade it’s releasing approximately 5 billion metric tons of CO2 from decomposing trees. And as the Amazon forests die, the Earth also loses its vast cloud-making machines forcing it to absorb incoming solar radiation rather than reflect it.
In 2009, the United States alone emitted 5.4 billion metric tons of CO2 from fossil fuel use. Scientists have documented that greenhouse gas emissions have significantly altered global climate — increasing the frequency, duration and/or severity of drought and heat stress in 88 forests on every wooded continent on Earth. All forest types are suffering from a lethal combination of at least three factors: insects and diseases associated with elevated temperatures; the drying out of plants; and carbon starvation, that is, water-stressed trees are unable to photosynthesize, or make food.
Extreme droughts in North Africa are killing Atlas cedar from Morocco to Algeria. Heat and drought are battering the high-elevation tropical moist forests in Uganda, mountain acacia in Zimbabwe and centuries-old aloe plants in Namibia. Tropical forests of Malaysia and Borneo have also suffered significant death. Drought has also lambasted the tropical dry forests of northwest and southwest India, fir in South Korea, the junipers of Saudi Arabia, and pine and fir in central Turkey. Extensive areas of forest in two regions of China have now been recognized as being at a high threat of mortality in the ensuing years. Russia too has identified 187.8 million acres of high-threat forests whose trees are severely stress by drought. Australia has seen widespread death in acacia woodlands and eucalypt and Corymbia forests. New Zealand has documented drought-induced death in high-elevation beech forests. Oak, fir, spruce, beech and pines across Western Europe are dying too.
Rising greenhouse emissions are elevating temperatures and the occurrence of droughts across western North America. In turn, this is fueling the largest native bark beetle epidemic in modern or past times (dating back over 200 million years). Instead of absorbing CO2 about 30 billion mature trees are decaying and adding greenhouse gases to the ever-rising atmospheric pool.
Earth’s forests are its lifesupport system.
We need a carbon-tax in America and worldwide. And we need it now.