“Forests diebacks are taking place all around the world. The evidence is quite sobering,” said tropical biologist Daniel Nepstad of IPAM in Belem, Brazil.
This reinforces the urgent need to reduce emissions of fossils fuels and to develop a global land strategy to turn sources of CO2 into sinks for CO2, he said.
“Most of the evidence shows climate change is speeding up. Meanwhile political action on climate is slowing down,” Nepstad added.
–From a previous post on how the loss of trees to deforestation, drought and disease is accelerating climate change.
Stephen Leahy, International Environmental Journalist 
I’m sure rising temperatures are going to cause forest declines all over the world but let’s be accurate. That is not the underlying reason for global declines, YET, because although AVERAGE temperatures have risen, locally some places have cooled or risen very little. For instance the Eastern North America, where trees are dying at an incredibly and increasingly rapid rate over the past few years, have been in the middle of a cooling hole due to sulphate aerosol pollution according to a recent study. So WHAT is killing the trees in the entire Appalachian region?
AIR POLLUTION. Ozone is killing them. Ozone is a well-known toxin to people and is even more poisonous to vegetation. In addition to the cumulative damage caused over multiple seasons to trees, ozone causes annual crop yield and quality loss in the billions of dollars. Precursors are rising, the background level is increasing even in remote areas.
Another well-known mechanism of ozone injury is increased attacks from insects, disease and fungus, and decreased resistance to drought, wind and winter kill.
Why are foresters, biologists, ecologists and climate scientists so averse to stating a fact as obvious as tobacco smoking causes cancer?? You would think climate scientists would be concerned because as plants die off we will be losing a major carbon sink, marking a massive amplifying feedback to warming.