Global Warming and its effects on Planetary Climate

There is a lot of buzz on the planet about global warming and its adverse effects on planet’s ecology, our society and civilization at large. But what is all this debate about?

Thanks to the media attention, many people are concerned about global warming, but they do not know what to do about it. The first thing is to understand the problem and its apparent root cause: increase in the amount of Carbon Dioxide in planet’s atmosphere or is it?

According to Victor Miguel Ponce – “The concentration of carbon dioxide in the atmosphere determines to a large extent the present world climate, with temperature being an important component. Through geologic time, carbon dioxide entering the atmosphere from natural sources such as volcanic eruptions and weathering of rocks, has been gradually used by vegetation, through the process of photosynthesis. In the past two-and-a-half billion years, carbon has been temporarily stored above the Earth's surface as standing biomass and litter. During this time, excess quantities of carbon were permanently stored below the surface as fossil deposits of coal, petroleum, and natural gas”.

However, it is an opinion which although backed with some facts, is not unanimous.

There is a somewhat informational site from Environmental Defense Fund which provides arguments against the common misunderstandings that people (in general) have about global warming. It can be accessed here à Global Warming Myths and Facts. There even a climate atlas available on this site.

Even the National Geographic has covered this topic of literally global concern. So it is happening? The answer is emphatic yes. There is more and more energy being pumped into global weather/ climate system causing ever more violent weather – hurricanes, stronger monsoons, etc. An upsurge in the amount of extreme weather events, such as wildfires, heat waves, and strong tropical storms, is also attributed in part to climate change by some experts. Tragedy on human life is increasing since humanity is more spread and numerous on the planet now than it ever was in the entire history of our species or the planet.

T J Nelson provides an insight into cold facts (contrary to mass hysteria) about global warming in this illuminating article. I strongly recommend a reading. In this article, Nelson attempts to provide a balanced and scientific view of facts related to global warming. His assertion is essentially this – current hysteria about global warming is largely a hype created by media and certain so called scientific papers.

According to him – “Although carbon dioxide is capable of raising the Earth's overall temperature, the IPCC's predictions of catastrophic temperature increases produced by carbon dioxide have been challenged by many scientists. In particular, the importance of water vapor is frequently overlooked by environmental activists and by the media. The above discussion shows that the large temperature increases predicted by many computer models are unphysical and inconsistent with results obtained by basic measurements. Skepticism is warranted when considering computer-generated projections of global warming that cannot even predict existing observations”.

http://www.junkscience.com/Greenhouse/ tries to debunk the entire mythology around global warming. This article (or set of it) actually tries to delink the “greenhouse effect” and global warming and the entire concept of climate change. It is very reassuring to the skeptic in me that there are people out there who are actually questioning blind following and mass hysteria being created by certain circles.

So is there no cause for worry? Have humans caused this global warming? The opinion though not unanimous, is overwhelmingly in favor of human causality. To know in a more coherent manner, one has to understand a few facts first:

• There is general agreement amongst scientists of this planet that our planet was “The Earth” was formed about 4,540,000,000 years ago – that’s 4.54 billion years.
• At the time of beginning and for quite sometime after that, the Earth's atmosphere contained very little oxygen (less than 1% oxygen pressure).
• Popular belief among the scientific community has it that early plants started to develop more than 2 billion years ago, probably about 2,700,000,000.
• It is an established fact that through photosynthesis, plants uptake carbon dioxide into the biosphere as organic matter, and release oxygen as a byproduct.
• Through geological ages, oxygen accumulated gradually in the atmosphere, reaching a value of about 21% of atmospheric gases at the present time. So our planet and its current atmosphere were terra-formed slowly over millions of years and concerted action of biological agents. It is not a “natural” occurrence, rather it would be safe to put it in these terms – life shaped earth’s climate and atmosphere to suit itself and brought about the present distribution of gases which we breathe.
• It is also believed that through geological ages, surplus organic matter has been sequestered in the lithosphere as fossil organic materials (coal, petroleum, and natural gas).
• Early animals (the first organisms with external shells) started to develop around 600,000,000 years ago
• Animals operate in the opposite way than plants: they take up oxygen, burn organic matter (food), and release carbon dioxide as a byproduct
• Early humans (Australopithecus anamensis) began to develop about 4,100,000 years ago
• Cool climatic conditions have prevailed during the past 1,000,000 years. The species Homo sapiens evolved under these climatic conditions
• Homo sapiens, that’s us, dates back to no more than 400,000 years.
• Estimates for the variety Homo sapiens sapiens, to which all humans belong, range from 130,000 to 195,000 years old
• The concentration of carbon dioxide in the atmosphere was as low as 190 ppm during the last Ice Age, about 21,000 years ago.
• The last Ice Age began to recede about 20,000 years ago
• The agricultural revolution, where humans converted forests and rangelands into farms, began to develop about 10,000 years ago.
• The agricultural revolution caused a reduction in standing biomass in the biosphere and reduced the uptake of carbon dioxide in midlatitudinal regions, indirectly contributing, however so slightly, to global warming.
• The concentration of carbon dioxide in the atmosphere increased gradually from a low of 190 ppm 21,000 year ago, to about 290 ppm in the year 1900, i.e., at an average rate of 0.00478 ppm per year
• The industrial revolution, where humans developed machines (artificial animals, since they consume fuels, which are mostly organic matter), began in England about 240 years ago (1767).
• In October 1999, the world's population reached 6,000,000,000, which is double that of the year 1959 (the doubling occurred in 40 years)
• The global fleet of motor vehicles is estimated at 830,000,000 (2006).
• The global fleet of motor vehicles has been recently growing at the rate of 16,000,000 per year.
• Motor vehicles (cars, trucks, buses, and scooters) account for 80% of all transport-related energy use
• The concentration of carbon dioxide in the atmosphere, which was at 290 ppm in the year 1900, rose to 316 ppm in 1959, or at an average 0.44 ppm per year
• Measurements of the concentration of carbon dioxide since 1959 (316 ppm) have revealed an increase to 378 ppm in 2004, or at an average 1.38 ppm per year
• The concentration of carbon dioxide has increased an average of about 1.8 ppm per year over the past two decades
• The year 1998 was the warmest of record. The year 2002 was the second warmest (to that date). The year 2003 was the third warmest (to that date). The year 2004 was the fourth warmest (to that date). The year 2005 equaled 1998 as the warmest of record. The year 2007 equaled 1998 as the second warmest of record.
• About 75% of the annual increase in atmospheric carbon dioxide is due to the burning of fossil fuels
• The remaining 25% is attributed to anthropogenic changes in land use, which have the effect of reducing the net uptake of carbon dioxide. Anthropogenic changes in land use occur when forests are converted to rangelands, rangelands to agriculture, and agriculture to urban areas.
• Other patterns of land degradation--deforestation, overgrazing, over-cultivation, desertification, and salinization--reduce the net uptake of carbon dioxide, indirectly contributing, however slightly, to global warming.
  

What's could Happen?

A follow-up report by the IPCC released in April 2007 warned that global warming could lead to large-scale food and water shortages and have catastrophic effects on wildlife.

• Sea level could rise between 7 and 23 inches (18 to 59 centimeters) by century's end, the IPCC's February 2007 report projects. Rises of just 4 inches (10 centimeters) could flood many South Seas islands and swamp large parts of Southeast Asia.
• Some hundred million people live within 3 feet (1 meter) of mean sea level, and much of the world's population is concentrated in vulnerable coastal cities. In the U.S., Louisiana and Florida are especially at risk.
• Glaciers around the world could melt, causing sea levels to rise while creating water shortages in regions dependent on runoff for fresh water.
• Strong hurricanes, droughts, heat waves, wildfires, and other natural disasters may become commonplace in many parts of the world. The growth of deserts may also cause food shortages in many places.
• More than a million species face extinction from disappearing habitat, changing ecosystems, and acidifying oceans.
• The ocean's circulation system, known as the ocean conveyor belt, could be permanently altered, causing a mini-ice age in Western Europe and other rapid changes.
• At some point in the future, warming could become uncontrollable by creating a so-called positive feedback effect. Rising temperatures could release additional greenhouse gases by unlocking methane in permafrost and undersea deposits, freeing carbon trapped in sea ice, and causing increased evaporation of water.
  

We need to remember, Dinosaurs died out 65 million years ago – primarily due to climate change. It wasn’t only the asteroid which struck the earth and wiped out 99% species on land and oceans. It wasn’t just the impact – but the climate change induced by that impact which killed the species.

Can we do anything to stem this rising tide?

Sure! Just follow the tips on this wonderful blog. The Grinning planet provides some clues – which I would have anyway recommended even if our planet wasn’t threatened with global warming and so called catastrophic climate change!

Other resources:

• global-warming myths and facts at Undo-It.org
• climate change science at RealClimate.org