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• Wake Up, Freak Out - Then Get a Grip
• This really isn't about polar bears anymore. At this very moment, the fate of civilization itself hangs in the balance.
• The way we have been calculating the future impacts of climate change up to now has been missing a really important piece of the picture.
• We are now dangerously close to the tipping point in the world's climate system - this is the point of no return after which truly catastrophic changes become inevitable.
• For the past three million years, our planet's climate has always been in one or the other of two stable states


  1. Small changes in solar incidence pushed us from one to the other

  2. When we are in the cooler dip, the planet has an ice age

  3. When we are in the warmer one, the planet's climate is very much as it is now, and has been throughout the whole of human history
• Our use of fossil fuels is pushing us further and further out of our little stable dip and up the far slope of this hill.
• The tipping point is the point at which we cross the peak of the hill, and we no longer need to keep pushing to keep the planet moving towards a much hotter place. It will just keep rolling onwards, all on its own.
• Positive feedbacks in the climate systems


  • Mechanisms that can amplify the effects of man-made warming and lead to runaway change
• Albedo Effect


  White surfaces reflect more solar radiation than dark surfaces, so as global warming from greenhouse gases melts ice and snow, it leaves behind dark ocean or land which absorb more solar radiation, adding to warming which melts more ice and snow, and so on
• Uncondensed water vapour


  A more important greenhouse gas than CO2
• As the planet warms

  Evaporation rates increase, raising humidity and thickening the Earth's thermal blanket which in turn raises temperatures, which further increases evaporation rates
• Normally, about half the CO2 emitted each year from human activities is re-absorbed by a combination of forests, plankton, and the ocean itself.
• The ocean surface is becoming more and more acidic as concentrations of CO2 dissolved in it rise.
• At the same time the water temperature at the surface is also going up, forming a layer of warm, acidic water that is spreading across the ocean surface, killing off the plankton that locks CO2 out of the atmosphere.
• Warm water holds less CO2 than cold water so as it heats up, it starts releasing some of the CO2 it had previously absorbed.
• As land-based ecosystems heat up

  They become unbalanced - plants become less effective while micro-organisms in the soil become more effective at putting out carbon, causing the ecosystem as a whole to go from being a carbon sink to being a carbon source
• As temperatures rise and rains fail, forests dry out, and fires don't get put out. All of the forest's stored carbon goes up in smoke, adding to the greenhouse gases in the atmosphere, further increasing warming, which further degrades the carbon sinks.
• In Siberia, a vast area of frozen peat bog the size of France and Germany combined that we call the permafrost is melting, and as it melts, it releases huge quantities of methane.
• Methane


  A greenhouse gas with a short lifespan in the atmosphere but while there it has a warming effect more than 20 times as powerful as carbon dioxide
• The more methane is released


  The more it adds to warming, the more the permafrost melts, and the more methane is released
• Lurking under the sea bed there may be as much as 10 trillion tons of methane stored as frozen crystals at sites around the world.
• If we raise ocean temperatures by enough - and nobody knows how much is enough, we could trigger the sudden release of this stored methane into the atmosphere.
• The last time this happened, global temperatures rose abruptly by 10 degrees.
• So far we have only pushed up global temperatures by around 0.8°C but because of the 40 or 50 year time lag between emissions and temperature rise, the emissions already in the atmosphere commit us to raising temperatures by around another 0.6°C over the coming decades.
• If we do pass this critical threshold, global temperatures could soar by as much as 6°C.
• If this happens, the natural world will suffer a mass extinction event which will wipe out the majority of the plants and animals with which we share the planet.
• The first human impacts will come in the form of steeply declining access to fresh water, as rainfall patterns change, glacier-fed rivers dry up, and rising sea levels contaminate reservoirs.
• As crops fail, forests burn, deserts spread and coastal regions flood permanently, people will start to pack up their things in their billions and move on in search of a better life elsewhere.
• Humanity might survive this. But what will 'humanity' mean in a world where countries which will remain habitable like Britain, spend most of our resources fighting to keep out the starving millions who can no longer live in their own countries because of what we have done?
• The world is awash with weapons. Enough firearms to arm one in every seven human beings on the planet.
• As the world's ability to support the huge numbers of people alive today dwindles, we will not die peacefully in our sleep.
• None of this is inevitable – yet. This is not the time to panic or to despair. This is the time to act, while we still can.
• We need to recognize that there is a huge question mark over whether governments and corporations are capable of responding to this threat in the time we have left.
• They have had 20 years already and still have less than nothing to show for it.
• This is because they remain committed to a doctrine that prioritises short term profits and endless economic growth over the survival of life on earth.
• There is no great mystery about what we need to do to reduce emissions in line with the science. we simply need to consume less.
• But that is out of the question in a society which is founded on the ever-increasing consumption of material resources and energy.
• Nobody has all of the answers but we do know that this is not the only way to live, and given that it is almost certainly going to kill us all, we'd better start looking urgently at some of the alternatives.
• It's now very clear that in order to actually win the fight against climate change, making big changes to the way we each live our own lives is not going to be enough. we're also going to have to actively confront powerful vested interests who will stop at nothing to prevent the changes we need from taking place.
• We have to be more than just consumers.