"Global Warming Close to Becoming Irreversible"

The skeptics have decided that evidence isn't really evidence -- it's a grand conspiracy of thousands to fool the public -- so no amount of evidence will matter. Nevertheless, this is worth noting:

Global Warming Close to Becoming Irreversible, by Nina Chestney, Scientific American: The world is close to reaching tipping points that will make it irreversibly hotter ... scientists warned on Monday. ... As emissions grow,... the world is close to reaching thresholds beyond which the effects on the global climate will be irreversible ...

For ice sheets - huge refrigerators that slow down the warming of the planet - the tipping point has probably already been passed...

Most climate estimates agree the Amazon rainforest will get drier as the planet warms. Mass tree deaths caused by drought have raised fears it is on the verge of a tipping point, when it will stop absorbing emissions and add to them instead. Around 1.6 billion tons of carbon were lost in 2005 from the rainforest and 2.2 billion tons in 2010, which has undone about 10 years of carbon sink activity...

One of the most worrying and unknown thresholds is the Siberian permafrost, which stores frozen carbon in the soil away from the atmosphere. ... In a worst case scenario, 30 to 63 billion tons of carbon a year could be released by 2040, rising to 232 to 380 billion tons by 2100. This compares to around 10 billion tons of CO2 released by fossil fuel use each year.

Increased CO2 in the atmosphere has also turned oceans more acidic as they absorb it. In the past 200 years, ocean acidification has happened at a speed not seen for around 60 million years...