Archive by category | Extreme Events

Why a climate crisis is like an epileptic seizure

Why a climate crisis is like an epileptic seizure

Tipping points – those critical thresholds in a complex system where a small nudge can cause a catastrophic response – are perhaps the most fearsome threats to the Earth’s climate, but they also haunt ecosystems, financial markets, and even sufferers of medical conditions such as epilepsy and asthma. A fascinating review in Nature today (subscription) sketches out the mathematical patterns on which many of these instances seem to be based, and describes giveaway signs that might warn us to change course before the system tips.  Read more

AGU Chapman Conference: “They walked away”

AGU Chapman Conference: "They walked away"

At the AGU Chapman conference today, Yale archaeologist Harvey Weiss took the prize for an abrupt climate change picture worth a thousand words. Excavating an Akkadian palace in Tell Leilan, Syria, in 2006 and 2008, Weiss’s team found one room with a grain storage vessel smashed on the floor. Lying next to it were a standard litre measure used for rationing grain, and the tablet on which a bureaucrat had been recording the rationing. The artifacts date from about 2190 B.C., when cities and towns of the Akkadian empire in Mesapotamia were being abandoned en masse as the region suffered crushing drought.  Read more

AGU Chapman: Meridional madness

AGU Chapman: Meridional madness

Today’s theme at the AGU Chapman Conference on Abrupt Climate Change is that big baddie of climatic tipping points, the shutdown (and rebooting) of the Atlantic Meridional Overturning Circulation, or AMOC. Could this massive system go down again? Tom Delworth of NOAA took on that question and offered up some interesting new modelling evidence.  Read more

Greening vs. Gassing in the Arctic

Scientists have long debated how the global climate might be affected by thawing of the Arctic’s permanently frozen soils, known as permafrost. As permafrost melts, bacteria break down the organic matter in the soil, releasing greenhouse gases. But at the same time, plants flourish with access to warmer, deeper soils, taking in carbon dioxide. The overall affect on the climate was assumed to be the balance between the gassing and greening.  Read more

Will warming wash-away Wall Street?

Will warming wash-away Wall Street?

Cross-posted from The Great Beyond New Yorkers beware! A new study published in Nature Geoscience says the north-eastern US coast will be in more trouble from global warming than previously believed. Looking at the predictions from a whole set of different climate models, researchers Jianjun Yin, Michael Schlesinger and Ronald Stouffer found that changes in ocean circulation will result in higher sea levels in the region, over and above expected global sea level changes. Depending on whether greenhouse gas emissions are low or high, an additional rise of between 15 and 21 cm can be expected by 2100, they say.  Read more

Rapid retreat of Greenland’s outlet glaciers may be temporary

The loss of ice from Greenland ranks as one of the most troubling, and poorly understood, aspects of climate change. Melting of the colossal ice sheet, which is already undoubtedly underway, has the capacity to raise global sea levels by an astounding 7 meters.  Read more

AGU 2008: On the home front

I hadn’t anticipated quite so much rain during the AGU’s Fall conference in San Francisco, but apparently this exact week is, on average, the city’s wettest of the year. Or so I heard at today’s session on how the region is likely to be impacted by climate change.  Read more