Showing posts with label greenhouse gases. Show all posts
Showing posts with label greenhouse gases. Show all posts

Friday, October 3, 2014

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



Sunday, September 14, 2014

Climate Accord New York September 2014

Under the Obama administration, the U.S. has made some (small) progress limiting the amounts of greenhouse gases that states emit, e.g. through Environmental Protection Agency limits on carbon dioxide emitted by power plants.

Given that greenhouse gases do spread all over the globe, the U.S. must also support action abroad to reduce levels of greenhouse gases.

At the upcoming Climate Summit in New York, September 23, President Obama will have a good opportunity to do so.

President Obama can and should support an accord for nations to jointly commit to bold action, including the imposition of fees on fossil fuel exported to nations that fail to commit to such action.

Where necessary, World Trade Organization rules should be agreed to be adjusted in order to accommodate such fees.

An accord on export fees can help U.S. exporters remain competitive and avoid repercussions. Such fees will also help make importing nations impose fees domestically, as they will not want to miss out on the revenues from such fees.

Revenues from such fees are best held in a trust fund and they are best used exclusively to finance international projects, such as efforts to save the sea ice in the Arctic and R&D into ways to decompose methane. As more nations impose fees domestically and accept responsibility to participate in international projects, such export fees can phase themselves out.

The People's Climate March will take place on September 21, starting 11:30 am from Central Park West (between 65th and 86th streets). Whether or not you're taking part in the march, consider supporting the Climate Plan. If you print out above image, you could make a cardboard sign. Over the coming days, photos of people holding up such a sign can be posted and shared at facebook and, if you add some lines saying you like the idea, they will be considered for display at the Arctic-news blog. You can also make it your profile picture on facebook during the remainder of the month to get a chance to be mentioned as a supporter.  Thanks in advance.

Update of Sea Surface Temperature Anomaly below:



Thanks to all who liked, tagged and shared the top image. Two examples of how the message is shared are highlighted below.

Sheila Chambers at facebook                             

A.Randomjack at Google+




Monday, November 11, 2013

Methane Levels going through the Roof

On November 9, 2013, methane readings well over 2600 ppb were recorded at multiple altitudes, as illustrated by the image below.

[ click on image to enlarge ]
On November 9, 2013, p.m., methane readings were recorded as high as 2662 parts per billion (ppb), at 586 millibars (mb) pressure, which corresponds with an altitude of 14384.6 feet or 4384.4 meters.

Where did these high levels occur? Methane levels were low on the southern hemisphere and, while there were some areas with high readings over North America and Asia, there were no areas as wide and bright yellow as over the Arctic Ocean (the color yellow indicating readings of 1950 ppb and higher on above map).

As discussed in a previous post, huge amounts of methane are now escaping from the seabed of the Arctic Ocean, penetrating the sea ice, and entering the atmosphere, in a process that appears to be accelerating, resulting in huge amounts of methane in the atmosphere over the Arctic Ocean.

The image below gives an idea of the height of this level, compared to historic levels, and how fast levels of methane (CH4) have been rising compared to levels of two other greenhouse gases, i.e. carbon dioxide (CO2) and nitrous oxide (N2O).


Recent peak levels of methane over the Arctic Ocean may well have been even higher, since NOAA didn't release any readings for November 5-7, 2013.

Meanhwile, sea ice extent has stopped growing, as illustrated by the NSIDC graph below.


Data from the Cryosphere Today show that the area covered by sea ice has actually fallen over the past few days, as illustrated by the image below.

[ click on image to enlarge ]
There are several reasons why sea ice isn't growing, including high temperature anomalies in the Arctic, as illustrated by the NOAA image below, showing surface temperature anomalies of over 20 degrees Celsius on November 7, 2013.


High methane levels are contributing to temperature anomalies, by trapping additional sunlight in the atmosphere over the Arctic Ocean.

Furthermore, strong winds have hit the sea ice, as the recent post Methane, Faults and Sea Ice warned. Strong winds are pushing sea ice inward in the Kara Sea and in the Chukchi Sea, while pushing sea ice - up to 5 meters thick - out of the Arctic Ocean along the coast of Greenland, as illustrated by the Naval Research Laboratory animation below.


The Naval Research Laboratory image below shows ice speed and drift on November 9, 2013.


So, could Arctic sea ice collapse and totally disappear in September 2014? Posts at this blog have repeatedly warned about this, e.g. in this post. The image below, created by Wipneus, shows an exponential trendline pointing at zero volume sea ice in September 2016.
All data over the past two decades have fallen within the 95% confidence limits of an exponential trendline that points at imminent loss of all Arctic sea ice within years. September 2013 may have been "only" the 4th lowest on record, but such variability can be expected and may well cause sea ice to disappear completely as early as September 2014.

Strong winds can speed up such a collapse. On this point, it's good to remember what Prof. Peter Wadhams warned about in 2012:
". . apart from melting, strong winds can also influence sea ice extent, as happened in 2007 when much ice was driven across the Arctic Ocean by southerly winds (not northerly, as she stated). The fact that this occurred can only lead us to conclude that this could happen again. Natural variability offers no reason to rule out such a collapse, since natural variability works both ways, it could bring about such a collapse either earlier or later than models indicate.

In fact, the thinner the sea ice gets, the more likely an early collapse is to occur. It is accepted science that global warming will increase the intensity of extreme weather events, so more heavy winds and more intense storms can be expected to increasingly break up the remaining ice, both mechanically and by enhancing ocean heat transfer to the under-ice surface."
Guy McPherson lists 26 feedbacks that speed up warming, and many of these feedbacks occur in the Arctic, as described in the post Diagram of Doom.

Soon, calculates Prof. Peter Wadhams, the albedo loss due to decline of snow and ice in the Arctic will effectively more than double the net radiative forcing resulting from the emissions caused by all people of the world. Additional warming caused by methane releases from the Arctic seabed could be even more devastating.

Hopefully, more people will realize the urgency of the situation and realize the need for a comprehensive and effective plan of action as described here.