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Climate ChangeDisasters & Extreme WeatherGlobal WarmingNatureScience

$60 Trillion — Global Economic Impact Of A Massive Methane Release In The Arctic, New Study Shows

Up to $60 trillion (just shy of the global GDP for one year) is what climate change impacts will cost the world’s economy if the estimated 50 billion tons of seafloor-trapped methane gas in the East Siberian Arctic Shelf were to be released into the atmosphere.

That’s according to new economic modeling research conducted by economists at the University of Cambridge (UK) and Erasmus University in The Netherlands (and reported by Reuters). The team looked at several possible scenarios involving the release (out-gassing) of so much methane — a steady release over a decade, a “sudden” release (e.g., a methane mega “burp”), or even smaller and slower releases over 50 years. The team also assumed that the rate of annual global temperature increase would continue at its current pace.

arctic ocean features map
Arctic Ocean bathymetric features.
Image Credit: Mikenorton

“In all of these cases there is a steep global price tag attached to physical changes in the Arctic, notwithstanding the short-term economic gains for Arctic nations and some industries,” Gail Whiteman, Chris Hope, & Peter Wadhams write in the Nature article about the study.

These staggering costs will be due mainly to losses from flooding, drought, severe heat stresses and other disasters (called the “mean global climate impacts”).

And that’s just from the methane clathrate, or hydrate, gas (CH4) trapped in ice under the East Siberian Arctic Sea (shelf); there are other vast areas and amounts of trapped methane, buried under frozen seafloors, throughout the Arctic region. And then there’s the potential carbon “bomb” (of CO2 and CH4) from bacterial decomposition of plant matter in thawing permafrost soil.

At more than twenty times the heat-trapping capacity of CO2, a large quantity of methane gas (CH4), though shorter-lived in the atmosphere, can trigger a series of impacts that could have devastating, perhaps irreversible, consequences on the Earth’s climate, all centered on a warming Arctic. And all of these impacts translate into major damage to the world’s economy.

“The global impact of a warming Arctic is an economic time-bomb,” Reuters quoted Gail Whiteman — one of the authors of the report and a professor of sustainability, management, and climate change at the Rotterdam School of Management, Erasmus University — as saying.

Using a model known as PAGE09, researchers ran the simulation 10,000 times to assess the range of climate change risks through the year 2200, taking into account “sea-level changes, economic and non-economic sectors and discontinuities such as the melting of the Greenland and West Antarctic ice sheets.”

The figure of $60 trillion is just 15% of the mean total predicted cost of climate-change impacts (about $400 trillion).

Quoting from the paper:

“In the low-emissions case, the mean net present value of global climate-change impacts is $82 trillion without the methane release; with the pulse, an extra $37 trillion, or 45% is added. These costs remain the same irrespective of whether the methane emission is delayed by up to 20 years, kicking in at 2035 rather than 2015, or stretched out over two or three decades, rather than one. A pulse of 25 Gt of methane has half the impact of a 50 Gt pulse.” [emphasis added]

The researchers estimate the cost to be even greater than this if one factors into the equation the effects of ocean acidification (the collapse of reefs, fish stocks, etc.). The researchers acknowledge that their results are best estimations and that to get better results, they need better models which incorporate additional “feedbacks,” such as those produced by increased shipping and oil and gas exploration and development*. This industrial impact/feedback is quite likely, as the authors point out that “the Arctic is thought to be home to 30% of the world’s undiscovered gas and 13% of its undiscovered oil.”

*The generation of black carbon from shipping and gas flaring absorbs solar radiation, increases surface heating, and can speed up ice melting.

Who Bears The Financial Burden?

Although this cost is the result of greenhouse gas emissions primarily coming from the developed world, and more recently the hyper-developing world (like China, India, and Brazil), up to 80% of this cost will be born by the poorer economies of Africa, Asia, and South America.

These less developed and less wealthy economies will be forced to spend (and borrow against) their national treasuries to mitigate, restore, and/or repair damage to agriculture, forest and ocean ecosystems, and habitable land. There will be additional massive costs due to disease (made worse by climate change impacts), climate refugees, and water/food insecurities.

The report highlights a growing, global issue of deep concern: this great inequality of responsibility verses impact is prompting many developing world leaders to formally protest on the basis of Climate Justice and/or Climate Debt.

What’s The Risk And The Reality?

A field study from 2010 (Sharkova et al) of the out-gassing of methane gas from the Eastern Siberian Arctic Shelf showed that, while there are several super-saturated methane “hot spots” in the water column, and the sea-floor appears to be perforated in large areas, so far, the ocean-air mixing of gases (CH4, CO2, etc.) in this region appears to be stable; there is yet no net increase in atmospheric methane in this region, although the scientists involved in this 2010 study recommend continuous monitoring of the shelf (note: not all dissolved methane gets released back into the air, this depends on the temperature of the water and the atmospheric pressure above the sea).

However, an increase in sea-floor temperature could accelerate the thawing of the hydrate and thus the rate and volume of methane gas release, and this could “speed up sea-ice retreat, reduce the reflection of solar energy and accelerate the melting of the Greenland ice sheet,” according to the paper. “The ramifications will be felt far from the poles.”

According to the Nature report, this event would likely speed up the date at which the global mean temperature would hit 2° Celsius above pre-industrial levels (i.e., sometime in the next 15 to 35 years if we choose a “business as usual” approach to GHG emissions), but if we choose to reduce emissions globally (a “low emissions” scenario), this date could be pushed back to 2040 — but we would still only have a 50% chance of keeping things cooler than 2°C until century’s end.

While some climatologists cite a 3°C increase limit (for the century) as being the “breaking point” for permanent (and irreversible) global climate change, others are more conservative, and use the 2°C mean global temperature increase as the critical threshold. Due to inherent variations in local conditions, estimating when temperature changes will happen (assuming we do nothing to curb current rates of GHG emissions) is a matter of calculating probabilities based upon known factors and giving time ranges over which certain changes could occur. This study only uses methane in the East Siberian Arctic Shelf sea floor, and global mean temperature rate, as its climate inputs.

However, the Reuters article references a recent study by the International Energy Agency (IEA) warning that at current (increasing) emission rates, we are on track to a 3.6°C–5.3°C increase by century’s end.

And there is another factor at play here: energy exploration. If we allow unfettered, unregulated drilling in this sensitive area, it is possible that already perforated areas of the shelf will be further perturbed, and this may likely accelerate the release of trapped gas and its predicted impacts.

Given the IEA estimate, and depending upon the “scenario” we choose, it may well mean that we will see the results of our global experiment with climate warming within many of our lifetimes, certainly our children’s lifetimes.

The paper “Climate science: Vast costs of Arctic change” (Whiteman, Hope, Wadhams) was published today in the journal Nature.

Material for this post also came from the Reuters news release (via The Huffington Post): “Arctic Methane Release Due To Climate Change Could Cost Global Economy $60 Trillion, Study Reports” by Nina Chestney




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