Where we are - A climate system summary

by Paul Beckwith

Air

The presence of GHGs (greenhouse gases) in the atmosphere is vital to sustain life on our planet. These GHGs trap heat and keep the global average surface temperature of the planet at about 15°C, versus a chilly -18°C, which would be our temperature without the GHGs.

We have changed the chemistry of the atmosphere, specifically of the concentrations of the GHGs. Concentrations of carbon dioxide have increased about 40% since the start of the industrial revolution (from a tight range between 180 to 280 ppm over at least the last million years) to 400 ppm. Concentrations of methane have increased by more than 2.5x since the start of the industrial revolution (from a tight range of 350 to 700 ppb) to over 1800 ppb. The additional heat trapped has warmed our planet by over 0.8°C over the last century, with most of that rise (0.6°C) occurring in the last 3 or 4 decades.

Oceans

Over 90% of the heat trapped on the surface of the planet is increasing the temperature of the ocean water. The increased levels of carbon dioxide in the atmosphere acidify the rainfall, and have increased the acidity of the oceans by about 40% in the last 3 to 4 decades (pH of the open ocean has dropped from 8.2 down to 8.05 on the logarithmic scale). An increased drop to a pH of 7.8 will prevent calcium based shells from forming, and threaten the entire food chain of the ocean. Changes in ocean currents, and vertical temperature profiles are leading to more stratification and less overturning which is required to transport nutrients to the surface for phytoplankton to thrive.

Global sea levels are presently rising at a rate of 3.4 mm per year, compared to a rate of about 2 mm per year a few decades ago. Melt rates on Greenland have doubled in the last 4 to 5 years, and melt rates on the Antarctica Peninsula have increased even faster. Based on the last several decades, melt rates have had a doubling period of around 7 years or so. If this trend continues, we can expect a sea level rise approaching 7 meters by 2070.

From: More than 2.5 m sea level rise by 2040

Land

Higher global average temperatures have increased the amount of water vapor in the atmosphere by about 4% over the last several decades, and around 6% since the start of the industrial revolution. Changes in heat distribution with latitude from uneven heating with latitude has slowed the jet streams and caused them to become wavier and fractured, and has changed the statistics of weather. We now have higher frequencies, intensities, and longer duration extreme weather events and also a change in location of where these events occur.

Feedback loops

The sensitivity of the climate system to increased levels of GHG appears to be much higher than previously expected due to many powerful reinforcing feedbacks.

From: Arctic Warming due to Snow and Ice Demise

Arctic temperature amplification from exponentially declining sea ice and spring snow cover are the strongest feedbacks in our climate system today. The average albedo (reflectivity) of the Arctic region has decreased from 52% to a present day value of 48% over 3 or 4 decades. The increased absorption of energy in the Arctic has increased the temperature at high latitudes at rates up to 6 to 8x the global average temperature change. The reduced temperature difference between the Arctic and equator has reduced the west to east speed of the jet streams causing them to slow and become wavier and more fractured, and directly causing a large change in the statistics of our global weather.

Methane gas emissions have been rapidly rising in the Arctic region from the terrestrial permafrost and the continental shelf marine sediments, most notably on the ESAS (Eastern Siberia Arctic Shelf). The extremely potent ability of methane to warm the planet (global warming potential GWP is >150, 86, and 34 times for methane relative to carbon dioxide on a few year, several decade, and century timescale, respectively) makes increased emissions an extremely dangerous risk to our well-being on the planet.

My overall assessment

Our climate system is presently undergoing preliminary stages of abrupt climate change. If allowed to continue, the planet climate system is quite capable of undergoing an average global temperature increase of 5°C to 6°C over a decade or two. Precedence for changes at such a large rate can be found at numerous times in the paleo-records. From my chair, I conclude that it is vital that we slash greenhouse gas emissions and undergo a crash program of climate engineering to cool the Arctic region and keep the methane in place in the permafrost and ocean sediments.

Paul Beckwith

Paul Beckwith is part-time professor with the laboratory for paleoclimatology and climatology, department of geography, University of Ottawa. Paul teaches climatology/meteorology and does PhD research on 'Abrupt climate change in the past and present'. Paul holds an M.Sc. in laser physics and a B.Eng. in engineering physics and reached the rank of chess master in a previous life. Click here to view Paul's earlier posts at the Arctic-news blog.


Related

- What's wrong with the weather?
http://arctic-news.blogspot.com/2014/07/whats-wrong-with-the-weather.html

- Arctic News: Polar jet stream appears hugely deformed
http://arctic-news.blogspot.com/2012/12/polar-jet-stream-appears-hugely-deformed.html

Post by Sam Carana.

State Of Extreme Emergency

by Malcolm Light

PRESIDENT OBAMA MUST DECLARE A STATE OF EXTREME NATIONAL EMERGENCY AND CEASE ORCHESTRATING A WAR WITH RUSSIA. HE MUST RECALL HIS ENTIRE ARMY AND NAVY PERSONNEL TO THE UNITED STATES TO BEGIN A MASSIVE CONVERSION OF THE US ENERGY SYSTEM TO SOLAR AND WIND POWER. THIS CONVERSION MUST RESULT IN ALL 600 COAL POWER STATIONS AND NUCLEAR STATIONS BEING COMPLETELY SHUT DOWN IN THE NEXT 5 TO 10 YEARS. ALL SURFACE TRANSPORT BOTH PRIVATE AND PUBLIC MUST BE ENTIRELY ELECTRIFIED AND AIR TRANSPORT CONVERTED TO METHANE OR HYDROGEN FUEL. IF THIS IS NOT DONE, HUMANITY WILL BE FACING TOTAL EXTINCTION IN AN ARCTIC METHANE FIRESTORM BETWEEN 2040 AND 2050.

The US and Canada must cut their global emissions of carbon dioxide by 90% in the next 10 to 15 years, otherwise they will be become an instrument of mass destruction of the Earth and its entire human population. Recovery of the United States economy from the financial crisis has been very unsoundly based by the present Administration on an extremely hazardous "all of the above" energy policy that has allowed continent wide gas fracking, coal and oil sand oil mining and the return of widespread drilling to the Gulf. Coast. This large amount of fossil fuel has to be transported and sold which has caused extensive spills, explosions and confrontations with US citizens over fracking and the Keystone XL pipeline. Gas fracking is in the process of destroying the entire aquifer systems of the United States and causing widespread earthquakes. The oil spills are doing the same to the surface river run off.

We are now facing a devastating final show down with Mother Nature, which is being massively accelerated by the filthy extraction of fossil fuels by US and Canada by gas fracking, coal and tar sand mining and continent wide bitumen transport. The United States and other developed nations made a fatal mistake by refusing to sign the original Kyoto protocols. The United States and Canada must now cease all their fossil fuel extraction and go entirely onto renewable energy in the next 10 to 15 years otherwise they will be guilty of planetary ecocide - genocide by the 2050's.

The volume transport of the Gulf Stream has increased by three times since the 1940's due to the rising atmospheric pressure difference set up between the polluted, greenhouse gas rich air above North America and the marine Atlantic Air. The increasingly heated Gulf Stream with its associated high winds and energy rich weather systems then flows NE to Europe where it recently pummeled Great Britain with catastrophic storms. Other branches of the Gulf Stream then enter the Arctic and disassociate the subsea Arctic methane hydrate seals on subsea and deep high - pressure mantle methane reservoirs below the Eurasian Basin- Laptev Sea transition. This is releasing increasing amounts of methane into the atmosphere producing anomalous temperatures, greater than 20°C above average. Over very short time periods of a few days to a few months the atmospheric methane has a global warming potential from 1000 to 100 times that of carbon dioxide.

There are such massive reserves of methane in the subsea Arctic methane hydrates, that if only a few percent of them are disassociated, they will lead to a jump in the average temperature of the Earth's atmosphere by 10°C and produce a "Permian" style major extinction event which will kill us all. The whole northern hemisphere is now covered by a thickening atmospheric methane global warming veil that is spreading southwards at about 1 km a day and it already totally envelopes the United States. A giant hole in the equatorial ozone layer has also been discovered in the west Pacific which acts like an elevator transferring methane from lower altitudes to the stratosphere where it already forms a dense equatorial global warming stratospheric band that is spreading into the Polar regions.

During the last winter, the high Arctic winter temperatures and pressures have displaced the normal freezing Arctic Air south into Canada and the United States producing never before seen, freezing winter storms and massive power failures. When the Arctic ice cap finally melts towards the end of next year, the Arctic sea will be aggressively heated by the sun and the Gulf Stream. The cold Arctic air will then be confined to the Greenland Ice cap and the hot globally warmed Arctic air with its methane will flow south to the United States to further heat up the Gulf Stream, setting up an anticlockwise circulation around Greenland. Under these circumstances Great Britain and Europe must expect even more catastrophic storm systems, hurricane force winds and massive flooding after the end of next year due to a further acceleration in the energy transport of the Gulf Stream. If this process continues unchecked the mean temperature of the atmosphere will rise a further 8° centigrade and we will be facing global deglaciation, a more than 200 feet rise in sea level rise and a major terminal extinction event by the 2050's.

Post by Zaven Ohannessian.

Runaway Global Warming

If you like, you can order prints of above image at Shutterfly (8 x 10 size works best).

Video and poster - methane in the Arctic

Methane in the Arctic threatens to escalate into runaway global warming.

The poster shown in the video is added below. 

Click on the poster to view a higher-resolution version, for printing out and hanging it on the wall.

Methane in the Arctic

Methane is often said to have a Global Warming Potential (GWP) of 21 times as strong as carbon dioxide, a figure based on IPCC assessment reports that date back to the 1990s. However, the IPCC has updated methane's GWP several times since, as illustrated in Table 1. below.

In its Fourth Assessment Report (AR4, 2007), the IPCC gives methane a GWP of 25 as much as carbon dioxide over 100 years and 72 as much as carbon dioxide over 20 years.

Furthermore, a 2009 study, by Drew Shindell et al., points out that the IPCC figures do not include direct+indirect radiative effects of aerosol responses to methane releases that increase methane's GWP to 105 over 20 years when included

Moreover, in the context of tipping points, which seems appropriate regarding methane releases in the Arctic, it makes sense to focus on a short time horizon, possibly as short as a few years.

Accordingly, methane's GWP can best be visualized as in the image below, which is also displayed mid-right on the poster above.

The image on the left shows methane's global warming potential (GWP) for different time horizons, pointing out that methane's GWP is more than 130 times that of carbon dioxide over a period of ten years.

IPCC¹ figures were used to create the blue line. The red line is based on figures in a study by Shindell et al.², which are higher as they include more effects. This study concludes that methane's GWP would likely be further increased by including ecosystem responses.

The ecosystem response can be particularly strong in the Arctic, where the seabed contains huge amounts of methane. Continued warming in the Arctic can cause large abrupt methane releases which in turn can trigger further methane releases from sediments under the sea.

This is particularly worrying, not only because of the presence of huge amounts of methane, but also because the sea is quite shallow in areas such as the East Siberian Arctic Shelf (ESAS), which in the case of large abrupt releases can soon lead to oxygen depletion in the water and make that much of the methane will enter the atmosphere without being oxidized in the water.

Additionally, low water temperatures and long sea currents in the Arctic Ocean are not very friendly toward bacteria that might otherwise break down methane in the water.

For further background, also see the post The potential impact of large abrupt release of methane in the Arctic at the Arctic Methane blog³, and the FAQ page at that blog.

References:

1. IPCC, Climate Change 2007: Working Group I: The Physical Science Basis, Table 2.14 (2007)
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-10-2.html

2. D.T. Shindell et al., "Improved Attribution of Climate Forcing to Emissions". Science vol 326: pp. 716-718 (2009)
http://www.sciencemag.org/content/326/5953/716.abstract

3. Sam Carana, The potential impact of large abrupt release of methane in the Arctic (2012)
http://arcticmethane.blogspot.com/2012/05/potential-impact-of-large-abrupt.html