Showing posts with label AR-5. Show all posts
Showing posts with label AR-5. Show all posts

Tuesday, November 4, 2014

Oceans and IPCC AR-5

From the IPCC AR-5 Summary for Policymakers Report, following is a statement about how the oceans are involved in absorbing the added heat input from the greenhouse gas effect:

Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010 (high confidence), with only about 1% stored in the atmosphere. On a global scale, the ocean warming is largest near the surface, and the upper 75 m warmed by 0.11 [0.09 to 0.13] °C per decade over the period 1971 to 2010. It is virtually certain that the upper ocean (0−700 m) warmed from 1971 to 2010, and it likely warmed between the 1870s and 1971. 

And a significant additional change is also taking place....ocean acidification:

Since the beginning of the industrial era, oceanic uptake of CO2 has resulted in acidification of the ocean; the pH of ocean surface water has decreased by 0.1 (high confidence), corresponding to a 26% increase in acidity, measured as hydrogen ion concentration. 

Two observable effects from these changes are, one, sea level rise due to thermal expansion of the warming oceans, and two, deterioration of marine ecosystems dependent on calcified exoskeletons, such as shellfish and coral reefs.

So is there any good news from the oceans? I think there is a lot, and one specific item is Ocean Thermal Energy Conversion, or OTEC. More on that in my next post. 

And below, a few pics of zero carbon energy generation based at sea. The top pic is of the Pelamis wave powered electric generator, and bottom, sea based wind turbines. 
Source: BBC article, In Pictures: Green Energy Awards photography contest.


 

Sunday, November 2, 2014

Climate Change 2014: IPCC's Fifth Assessment Report (AR-5)

The Intergovernmental Panel on Climate Change (IPCC) on Nov 1, 2014 released a new report titled:
Climate Change 2014
Synthesis Report
It is available in 2 versions: a shorter version of 40 pages for policy makers, and a longer version of 116 pages. Both can be accessed HERE.

Even the shorter version for policymakers is very technical (but I am sure our policymakers have good technical people on their staff). Also many referenced figures are not yet included, and every page has a disclaimer at the bottom saying, "Subject to copy editing and layout".

Even so, there is a vast amount of current information on climate change prepared by some of the world's most qualified scientists. I will begin a series of posts on this subject by quoting a few highlights, then in subsequent posts I will focus on the oceans involvement, as I will be doing a class on The World's Oceans and Climate Change for Osher Lifelong Learning (Lewes, DE) in the spring of 2015.

Following are two paragraphs from page 3 of the 40 page summary for policy makers:

1.1 Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen.

Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. The period from 1983 to 2012 was likely the warmest 30-year period of the last 1400 years in the Northern Hemisphere, where such assessment is possible (medium confidence). The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.8 [0.65 to 1.06] °C over the period 1880 to 2012, when multiple independently produced data sets exist.

GREENLAND - Will probably be the focus of near term sea level rise

Greenland is almost all covered by a very thick glacial ice cap. If all of Greenland's ice either melted or slid into the oceans, sea le...