Feeding a Growing World

For those in the Osher Climate class, and for everyone else, here is a very good summary of the Earth's increasing dilemma as population grows, the planet warms, and food production becomes far more difficult to increase. From the Scientific American title link:

".....there can be no permanent progress in the battle against hunger until the agencies that fight for increased food production and those that fight for population control unite in a common effort," Borlaug said in his acceptance speech for the Nobel Peace Prize in 1970. "[Man] is using his powers for increasing the rate and amount of food production. But he is not yet using adequately his potential for decreasing the rate of human reproduction. The result is that the rate of population increase exceeds the rate of increase in food production in some areas."

For the healthy perspective:...."ultimately, a little change in diet might do a world of good. Global demand for beef is an inefficient way to get protein, possibly unhealthy, and a major driver of deforestation and greenhouse gas emissions. "

Antarctica Update

Since our last Osher class of Earth and Its Climate in 2031 included a lot of material on the Antarctic, I thought the above title link might be of interest. Satellite technology certainly has done so much to help us visual learners.

For another visual feast, see The Canyon.

Warming Climate and Smaller Species

My first reaction was disbelief, but then after reading the article, I now wonder if the relationship may indeed be true. The cause and effect is made primarily through changes in weather, with less rainfall occurring in many parts of the world, leading to smaller plant species, followed by smaller herbivores, followed by smaller carnivores. Shrinking species size is supported by fossil records from times when the Earth warmed.

From the NY Times linked article: "Dr. Bickford said the paper was intended as an non-alarmist appeal to the world’s ecologists to take notice. “No matter what else they’re doing in the field, we want more ecologists to pay attention to body size and take these measurements,” he explained."

CO2 and Global Temperature Long Term Relationship

If you too wonder why Co2 spikes lag temperature spikes by several hundred years, read the following and see the title link from which these quotes came:

"What is being talked about here is influence of the seasonal radiative forcing change from the earth’s wobble around the sun (the well established Milankovitch theory of ice ages), combined with the positive feedback of ice sheet albedo (less ice = less reflection of sunlight = warmer temperatures) and greenhouse gas concentrations (higher temperatures lead to more CO₂ leads to warmer temperatures)......... CO₂ might well be expected to lag temperature by about 1000 years, which is the timescale we expect from changes in ocean circulation and the strength of the “carbon pump” (i.e. marine biological photosynthesis) that transfers carbon from the atmosphere to the deep ocean."

For additional information from the IPCC.

Earth and Its Climate in 2031

Following is the schedule and plans for the fall 2011 Class with the above title at the Osher Lifelong Learning Institute at the University of Delaware in Lewes:

This will be a workshop style course with participants contributing their ideas. In the first class, Bill will present where he thinks the Earth’s climate will be in 2031 relative to rising sea levels. We will then discuss class interests relative to the Earth and its climate. In this fall’s 5 classes we will focus on what is taking place, and what is forecast to happen relative to Earth’s climate. Next spring, in a planned continuation of this course, we will discuss what can be done to reduce global warming, through reductions in greenhouse gas emissions, and through potential geoengineering approaches.

Oct 17 – Sea Level Rise
The focus of the first class will be the causes of sea level rise, how it is measured, what the known history is, and what the forecast is. The class will begin with a 45 min. presentation, the same as will be presented to the Friends of Overfalls on Oct 14 (mentioned so you don’t attend both presentations). After that, we will discuss what specific climate topics most interest the class, and finalize a tentative agenda for the remaining 4 weeks (Oct 24, Oct 31, Nov 7 and Nov 14).

Potential future class topics include, but are not limited to:
1. A hypothetical vision of a warmer Earth in 2031 (and 2100?) relative to:
    a. sea level rise (continued with thoughts from others in the class)
    b. agriculture changes and feeding a growing world
    c. population changes and climate refugees
    d. wildlife changes, on land and in the oceans
2. The role of forests in global warming
3. Tipping points, what are they and how likely is one to occur?
4. Also see index in this blog for more ideas about possible topics.

Bill Fintel
Instructor

Deep Oceans and Global Warming

"The planet’s deep oceans at times may absorb enough heat to flatten the rate of global warming for periods of as long as a decade even in the midst of longer-term warming, according to a new analysis led by the National Center for Atmospheric Research (NCAR)."

This new study includes very little actual data because there are very few measurements of deep (below 300 m) ocean temperatures. Its conclusions are based largely on sophisticated computer simulations:

"To track where the heat was going, Meehl and colleagues used a powerful software tool known as the Community Climate System Model, which was developed by scientists at NCAR and the Department of Energy with colleagues at other organizations. Using the model’s ability to portray complex interactions between the atmosphere, land, oceans, and sea ice, they performed five simulations of global temperatures.

The two scientists, who are coauthors on the new study, suggested that the oceans might be storing some of the heat that would otherwise go toward other processes, such as warming the atmosphere or land, or melting more ice and snow."

“This study suggests the missing energy has indeed been buried in the ocean,” Trenberth says. “The heat has not disappeared, and so it cannot be ignored. It must have consequences."

The Climate Significence of Forests

Trees absorb a great deal of atmospheric CO2 as they grow, but they also release a great deal when fallen leaves and dead trees decay. The net balance has been difficult to determine, but recently more accurate measurements show that the net CO2 absorption of all forests world wide is equal to approximately one quarter of all CO2 emitted by man. Thus forests are presently playing a major role in slowing the rise of atmospheric CO2.

One of the biggest concerns relative to forests is that they are coming under increasing stress due to a warmer and drier climate. In the southwest, this has been evident as major forests fires this past summer. In the Rockies and Canada pine bark beetles, no longer killed back by cold winters, have been devasting large tracks of evergreen forests. In the Amazon region, there have been two major droughts with many large trees dying.

The linked article by Justin Gillis in the NY Times provides an excellent detailed review of the role of forests, and the perils they face. On the bright side, Eastern US forests are doing very well, and even growing more rapidly than they used to due higher CO2 levels and longer growing seasons.

Solyndra Collapse

Perhaps you were as astounded by this recent headline story as I was. A good thorough description of what transpired can be found at the title link to an LA Times article.

It looks like there were multiple factors involved, such as over-exuberance for solar power, and a dramatic fall in the price of high grade silicon which is used in competing flat solar panels.

2011 Minimum Arctic Sea Ice Extent

Depending on your source, 2011 was either the 2nd lowest arctic sea ice extent, or the lowest. The title link is to the National Snow and Ice Data Center (NSIDC). Their satellite sensor, and the algorithms they use, show minimum sea ice extent for 2011 was 2nd to the all time minimum observed in 2007.

The University of Bremen uses a different sensor, on a different satellite, as well as different algorithms, and their analysis shows 2011 to be the lowest sea ice extent ever measured.

In a broader view, both these analyses show a consistent trend in loss of arctic sea ice since satellite measurements began in 1972. Current minimum sea ice extent is only 50% of what it was in 1972. Other data show that ice thickness is also decreasing.

Additional details from the University of Bremen study can be found in the press release link at their web site. From this press release: "Climate models show rather that the reduction is related to the man-made global warming which, due to the ice albedo effect, is particularly pronounced in the Arctic: an ice area melted by a small temperature increase will then as open water have a much darker surface, absorb more solar radiation than before, which causes additional heating.......

The ice maps of the University of Bremen show also that in this year, the Northwest and Northeast passages are ice free simultaneously (Figure 2). This had happed for the first time in 2008, and in 2009 the German shipping company Beluga has traveled it commercially for the first time."

Extreme Weather and Global Warming

Above photo from Inhabitat.com article about Hurricane Irene.

Extreme weather and global warming is a very controversial topic! But a topic worth thinking about, and studying, because the underlying science supports a link between the two. As the Earth warms, which essentially all climate science data supports is happening, more energy is present in the atmosphere, primarily in the form of water vapor, but also in the form of higher air temperatures. Water vapor is most significant, because as water vapor condenses, it releases its latent heat of evaporation, which then provides the energy that fuels major storm systems, such as hurricanes.

The title link and photo link provide additional perspectives on this relationship. Also note that it is integrated weather which defines climate and climate change, so it is not justified to attribute a single storm event to global warming. But a history of many more major storm events, can be ascribed to global warming with reasonable scientific certainty.

Earth's Energy Balance

The title link is to a NASA Earth Observatory page which discusses the July heat wave in the U.S. The article also provides some relatively easy to understand details about Earth's energy balance, and is conveniently summarized in the next-to-last paragraph:

"The temperature on any planet, including Earth, is controlled by energy from the Sun. The Sun provides an average 340 Watts per square meter to the Earth. That energy returns to space as either reflected energy or radiated heat. Over time, the total outgoing energy should equal the amount of energy coming in from the Sun. When incoming and outgoing energy don’t balance, Earth’s temperature will change until balance is restored."

Please note that it is easy to subscribe to postings from  NASA Earth Observatory on the linked page.