Threat to global food supply makes comprehensive action imperative

Climate change is strongly affecting the Arctic and the resulting changes to the polar vortex and jet stream are in turn contributing to extreme weather in many places, followed by crop loss at a huge scale.

The U.N. Food and Agriculture Organization (FAO) said in a September 6, 2012, forecast that continued deterioration of cereal crop prospects over the past two months, due to unfavourable weather conditions in a number of major producing regions, has led to a sharp cut in FAO’s world production forecast since the previous report in July.

The bad news continues: Based on the latest indications, global cereal production would not be sufficient to cover fully the expected utilization in the 2012/13 marketing season, pointing to a larger drawdown of global cereal stocks than earlier anticipated. Among the major cereals, maize and wheat were the most affected by the worsening of weather conditions.

The image below shows the FAO Food Price Index (Cereals), updated to October 2012.

Apart from crop yield, extreme weather is also affecting soils in various ways. Sustained drought can cause soils to lose much of their vegetation, making them more exposed to erosion by wind, while the occasional storms, flooding and torrential rain further contribute to erosion. Higher areas, such as hills, will be particularly vulnerable, but even in valleys a lack of trees and excessive irrigation can cause the water table to rise, bringing salt to the surface.

Fish are also under threat, in part due to ocean acidification. Of the carbon dioxide we're releasing into the atmosphere, about a third is (still) being absorbed by the oceans. Dr. Richard Feely, from NOAA’s Pacific Marine Environmental Laboratory, explains that this has caused, over the last 200 years or so, about a 30% increase in the overall acidity of the oceans. This affects species that depend on a shell to survive. Studies by Baumann (2011) and Frommel (2011) indicate further that fish, in their egg and larval life stages, are seriously threatened by ocean acidification. This, in addition to warming seawater, overfishing, pollution and eutrification (dead zones), causes fish to lose habitat and is threatening major fish stock collapse.

Without action, this situation can only be expected to deteriorate further, while ocean acidification is irreversible on timescales of at least tens of thousands of years. This means that, to save many marine species from extinction, geoengineering must be accepted as an essential part of the much-needed comprehensive plan of action.

Similarly, Arctic waters will continue to be exposed to warm water, causing further sea ice decline unless comprehensive action is taken that includes geoengineering methods to cool the Arctic. The image below shows the dramatic drop in sea ice extent (total area of at least 15% ice concentration) over the past 7 years, compared to the average 1972-2011, as calculated by the Polar View team at the University of Bremen, Germany. This illustrates that a firm commitment to a comprehensive plan of action can now no longer be postponed.

Methane emissions discovered in Arctic Ocean

Voice of Russia has just reported the following news:

Methane emissions discovered in Arctic Ocean

Tags: Sci-Tech, scientific researches, Arctic Ocean, World, Russia, News

15.09.2012, 13:34

Photo: RIA Novosti

Russian scientists have discovered spots in the Arctic Ocean where mass emissions of methane can be observed. According to the press-service of the expedition aboard The Viktor Buinitsky research vessel, the diameter of some of the ‘methane fields’ found in the northern part of the Laptev Sea exceeds 1 kilometre.The new discoveries will help to understand the mechanism of global warming on Earth, experts believe. In their opinion, emissions of methane could have catastrophic consequences for the climate of our planet. Читать далее Source: Voice of Russia.

The location of the Laptev Sea is indicated on the Wikipedia map below.

Below, methane level measurements for the period from September 7 to 12, 2012.

For comparison, the image below shows methane level measurements for the period from September 1 to 7, 2012. It shows there was less methane then, particularly in the region north of Siberia.

For more comparisons, see the recent post High September 2012 methane levels.

So, how serious is this? Well, have a look at the poster below (click to enlarge).

For background and for references, see this presentation

Arctic sea ice decline continues

The image below, from The Cryosphere Today, shows that Arctic sea ice has shrunk in area by 11.446871 million square km from March 28, 2012, to September 11, 2012, a fall of over 83.66 percent in 167 days.

The image below illustrates the dramatic drop in sea ice extent (total area of at least 15% ice concentration) for the last 7 years, compared to the average 1972-2011, as calculated by the Polar View team at the University of Bremen, Germany.

Russia: 74 million acres burned through August 2012

NASA image, acquired September 11, 2012

From NASA Earth Observatory
http://earthobservatory.nasa.gov/IOTD/view.php?id=79161

The summer of 2012 has proven to be the most severe wildfire season Russia has faced in a decade. Unlike 2010, when severe fires raged in western Russia, most of the fires in 2012 have burned through taiga in remote parts of eastern and central Siberia.

On September 11, 2012, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this image of fires burning in Tomsk, a region of south central Siberia where severe wildfires have burned throughout the summer. Thick smoke billowed from numerous wildfires near the Ob River and mixed with haze and clouds that arrived from the southwest. Red outlines indicate hot spots where MODIS detected the unusually warm surface temperatures associated with fires.

More than 17,000 wildfires had burned more than 30 million hectares (74 million acres) through August 2012, according to researchers at the Sukachev Institute of Forest in the Russian Academy of Sciences. In comparison, 20 million hectares burned last year, which was roughly the average between 2000 and 2008, according to an analysis of MODIS data published in 2010.

Another way to gauge the severity of a wildfire season is to consider the smoke emissions. Fires emit a range of gases and particles into the atmosphere that can be detected by ground-based, aircraft, and satellite instruments. The two most common emissions are carbon dioxide and water vapor; however, incomplete combustion also generates carbon monoxide, an odorless and poisonous gas. In fact, fires are the source of about half of all carbon monoxide in the atmosphere.

Though ground and aircraft sensors provide the most accurate measurements of carbon monoxide for a localized area, satellites offer the best way to monitor wildfire emissions over broad regions, particularly in remote areas where there are fewer ground-based instruments. Christine Wiedinmyer, a scientist at the National Center for Atmospheric Research, has developed a model that ingests MODIS observations of fires and combines them with other information about vegetation (such as the percentage of tree cover and the type of forest) to calculate the quantity of emissions.

In September 2012, Wiedinmyer used her model to calculate Russian fire emissions for every year dating back to 2002. She found that the amount of carbon monoxide produced in 2012 was significantly more than what was produced in 2010 and the second most in a decade. Through August 31, the model showed that Russian wildfires had released an estimated 48 teragrams of carbon monoxide since the beginning of 2012. By comparison, the model estimated fires yielded just 22 teragrams of carbon monoxide in all of 2010.

Only one year—2003—had higher overall emissions. In that year, when severe fires burned in eastern Russia, wildfires produced an estimated 72 teragrams of carbon monoxide.

References
- Wiedinmyer, C. (2011). The Fire Inventory from NCAR (FINN): a High Resolution Global Model to Estimate the Emissions from Open Burning. Geoscience Model Development.
- Vivhar, A. (2010, July 13). Wildfires in Russia in 2008-2008: Estimates of Burn Areas Using Satellite MODIS MCD45. Remote Sensing Letters.
- Langmann, B. (2009, July 13). Vegetation Fire Emissions and Their Impact on Air Pollution and Climate. Atmospheric Environment.

Further Reading
- Russian Government. (2012, August 6). Dmitry Medvedev on a Working Visit to the Tomsk Region Holds a Meeting on the Situation in the Constituent Entities of the Russian Federation Suffering from Abnormally High Temperatures in 2012.Accessed September 12, 2012.
- Russian Government. (2012, August 6). Dmitry Medvedev Holds a Meeting With Tomsk Region Governor Sergei Zhvachkin. Accessed September 12, 2012.
- Ranson, J. (2012, July). Siberia 2012: A Slow and Smoky Arrival. Notes from the Field.

NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response Team, Goddard Space Flight Center. Caption by Adam Voiland, with information from Christine Wiedinmyer, Jon Ranson, and Vyacheslav Kharuk. Instrument: Aqua - MODIS