Tag Archives: tipping points

Trouble at the top of the world

Arctic summer sea ice minimum was the sixth lowest on record. So we can all relax, right?

Wrong.

I’ll come back to that. However, Tamino at Open Mind points out that while the Arctic warms three to four times as fast as global warming, the Arctic winters are warming at a much faster rate.

Using the NASA data, which is about mid-range in the major players, Tamino finds that the overall average warming rate since 1985 in the Arctic, at 6.48°C/century is fully 3.4 times as fast as the global rate since 1985 of 1.90°C/century. Continue reading Trouble at the top of the world

Science shows the need for urgent climate action

In August last year in Climate clippings 181 (Item 5) I linked to a report by Climate Analytics examining the impacts on Australia of limiting global temperature rise to 1.5°C and 2°C.

For me the crux of the report is this, from a discussion piece at The Conversation:

    The report predicts that half of the world’s identified tipping points – such as the collapse of polar ice sheets and the drying out of the Amazon rainforest – would be crossed under 2C warming, compared with 20% of them at 1.5℃.

If we go to 2℃, we will have a very different climate and there is a good chance we won’t be able to stabilise there. The bad news is that if we just carry on we’ll reach 1.5C by 2024, and 2C by 2036. Continue reading Science shows the need for urgent climate action

Tipping point for climate action?

Recently the Climate Commission issued a report in its The Critical Decade series on Extreme Weather looking at the issues of

  • Heat
  • Bushfires
  • Rainfall
  • Drought, and
  • Sea level rise.

At Radio National’s The World Today Professor Lesley Hughes, a Macquarie University ecologist, talked to Eleanor Hall.

The report looks at extreme weather experience in recent times, such as that documented in the Commission’s report The Angry Summer, puts it in a broader context using the latest science and then uses that as a window to project into the future. The message is plain. The climate has shifted, expect more and more extreme weather and we need to act now.

we really need to view all these events not in isolation but as part of a trend for the future. We need to prepare for them and we need to do our absolute best to cut greenhouse gases to stabilise the climate to prevent them getting to the point at which we cannot adapt.(Emphasis added)

Continue reading Tipping point for climate action?

Climate clippings 39

Greenland ice

Predicting tipping points

Tim Lenton is now attempting to link the basic theory of climatic “tipping points” with observed early warning signals.

Problem is, these tipping points may not be sudden and dramatic but involve a steady but inevitable increase. When outbreaks of pine beetles first became obvious perhaps the eventual destruction of Canada’s boreal forests was inevitable. But Lenton is making an argument “from almost a mathematical point of view” that there are general properties of tipping points. Continue reading Climate clippings 39

Climate clippings 15

These posts include a brief mention of a number of news items relating to climate change. They don’t preclude treating any of these topics at more length in a separate post.

They can also serve as an open thread so that we can keep each other informed on important climate news.

Beware the collapse of the planet’s lungs

Amazon drought is consistent with what scientific models predict for a warmer globe.

Normally, rainforests function like great carbon sinks, absorbing a large proportion of the CO2 that human activity produces. But in 2005, thanks to deforestation, the Amazon became a net emitter of carbon dioxide. In that year, the rainforest is estimated to have emitted some 5 billion tonnes of CO2, almost as much as the entire output of the United States.

Continue reading Climate clippings 15