Causes of global warming, Effects of global warming:

Global warming and climate change are phrases that have been around for some time now, and refer to the warming of Earth's atmosphere resulting in higher world temperatures. Each chapter in this book deals with a specific and relevant aspect of the problem, from the Amazon Rainforest to How do hurricanes form. Earth's atmosphere comprises many gases, collectively called Greenhouse gases. The greenhouse effect created by these gases maintains the Earth at a comfortable 15 degrees Celsius. Without the greenhouse effect the Earth would be a chilly minus 18 degrees Celsius.

Since the industrial revolution we know from ice core records that carbon dioxide levels were about 280 parts of CO2 per million parts of air (ppm). As a result of industrialisation resulting in deforestation for agriculture and settlements and burning fossil fuels levels of greenhouse gases have increased by 37% to about 385 ppm.

Solar variation

Variations in solar output have been the cause of past climate changes, but solar forcing is generally thought to be too small to account for a significant part of global warming in recent decades. Greenhouse gases and solar forcing affect temperatures in different ways. While both increased solar activity and increased greenhouse gases are expected to warm the troposphere, an increase in solar activity should warm the stratophere while an increase in greenhouse gases should cool the stratosphere.

Observations show that temperatures in the stratosphere have been cooling since 1979, when satellite measurements became available. Radiosonde(weather balloon) data from the pre-satellite era show cooling since 1958, though there is greater uncertainty in the early radiosonde record.

A related hypothesis, proposed by Henrik Svensmark, is that magnetic activity of the sun deflects cosmic rays that may influence the generation of cloud condensation nuclei and thereby affect the climate. Other research has found no relation between warming in recent decades and cosmic rays. A recent study concluded that the influence of cosmic rays on cloud cover is about a factor of 100 lower than needed to explain the observed changes in clouds or to be a significant contributor to present-day climate change.

Greenhouse gases

The greenhouse effect is the process by which absorption and emission of infrared radiation by gases in the atmosphere warm a planet's lower atmosphere and surface. It was discovered by Joseph Fourier in 1824 and was first investigated quantitatively by Svante Arrhenius in 1896. Existence of the greenhouse effect as such is not disputed, even by those who do not agree that the recent temperature increase is attributable to human activity. The question is instead how the strength of the greenhouse effect changes when human activity increases the concentrations of greenhouse gases in the atmosphere.

Naturally occurring greenhouse gases have a mean warming effect of about 33 °C (59 °F). The major greenhouse gases are water vapor, which causes about 36–70 percent of the greenhouse effect; carbon dioxide (CO₂), which causes 9–26 percent; methane (CH₄), which causes 4–9 percent; and ozone (O₃), which causes 3–7 percent. Clouds also affect the radiation balance, but they are composed of liquid water or ice and so are considered separately from water vapor and other gases.

Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO₂, methane, tropospheric ozone, CFCs and nitrous oxide. The concentrations of CO₂ and methane have increased by 36% and 148% respectively since 1750. These levels are much higher than at any time during the last 650,000 years, the period for which reliable data has been extracted from ice cores. Less direct geological evidence indicates that CO₂ values higher than this were last seen about 20 million years ago. Fossil fuel burning has produced about three-quarters of the increase in CO₂ from human activity over the past 20 years. Most of the rest is due to land-use change, particularly deforestation.

CO₂ concentrations are continuing to rise due to burning of fossil fuels and land-use change. The future rate of rise will depend on uncertain economic, sociological, technological, and natural developments. Accordingly, the IPCC Special Report on Emissions Scenarios gives a wide range of future CO₂ scenarios, ranging from 541 to 970 ppm by the year 2100 (an increase by 90-250% since 1750). Fossil fuel reserves are sufficient to reach these levels and continue emissions past 2100 if coal,tar sands or methane clathrates are extensively exploited.

The destruction of stratospheric ozone by chlorofluorocarbonsis sometimes mentioned in relation to global warming. Although there are a few areas of linkage, the relationship between the two is not strong. Reduction of stratospheric ozone has a cooling influence, but substantial ozone depletion did not occur until the late 1970s. Ozone in the troposphere (the lowest part of the Earth's atmosphere) does contribute to surface warming.

Temperature changes

The most common measure of global warming is the trend in globally averaged temperature near the Earth's surface. Expressed as a linear trend, this temperature rose by 0.74 ± 0.18 °C over the period 1906–2005. The rate of warming over the last half of that period was almost double that for the period as a whole (0.13 ± 0.03 °C per decade, versus 0.07 °C ± 0.02 °C per decade). The urban heat island effect is estimated to account for about 0.002 °C of warming per decade since 1900. Temperatures in the lower troposphere have increased between 0.13 and 0.22 °C (0.22 and 0.4 °F) per decade since 1979, according to satellite temperature measurements. Temperature is believed to have been relatively stable over the one or tw0 thousand years before 1850, with regionally varying fluctuations such as the Medieval Warm Period and the Little Ice Age. Estimates by NASA's Goddard Institute for Space Studies and the National Climatic Data Center show that 2005 was the warmest year since reliable, widespread instrumental measurements became available in the late 1800s, exceeding the previous record set in 1998 by a few hundredths of a degree. Estimates prepared by the World Meteorological Organization and the Climatic Research Unit show 2005 as the second warmest year, behind 1998. Temperatures in 1998 were unusually warm because the strongest El Nino in the past century occurred during that year. Global temperature is subject to short-term fluctuations that overlay long term trends and can temporarily mask them. The relative stability in temperature from 2002 to 2009 is consistent with such an episode.

Temperature changes vary over the globe. Since 1979, land temperatures have increased about twice as fast as ocean temperatures (0.25 °C per decade against 0.13 °C per decade). Ocean temperatures increase more slowly than land temperatures because of the larger effective heat capacity of the oceans and because the ocean loses more heat by evaporation. The Northern Hemisphere warms faster than the Southern Hemisphere because it has more land and because it has extensive areas of seasonal snow and sea-ice cover subject to ice-albedo feedback. Although more greenhouse gases are emitted in the Northern than Southern Hemisphere this does not contribute to the difference in warming because the major greenhouse gases persist long enough to mix between hemispheres.

The thermal inertia of the oceans and slow responses of other indirect effects mean that climate can take centuries or longer to adjust to changes in forcing. Climate commitment studies indicate that even if greenhouse gases were stabilized at 2000 levels, a further warming of about 0.5 °C (0.9 °F) would still occur.

How to implement simple steps against global warming

Global warming already disrupts millions of lives daily in the forms of destructive weather patterns and loss of habitat. What is already happening is only the tip of the melting iceberg, for it is our children and grandchildren who may suffer most from the effects of global warming. Hundreds of millions of people may be exposed to famine, water shortages, extreme weather conditions and a 20 - 30% loss of animal and plant species if we do not reduce the rate of global warming and reduce GHG emissions.

On the other hand, having warmer winters means longer growing seasons in temperate and subarctic climes, sometimes allowing an additional crop to be planted and harvested each year, or simply making the existing crops more productive. This article outlines some ways that you can act to help prevent the Earth from warming further. While humankind has the ability to destroy the planet, we can also help protect and sustain it.

Reducing your carbon and greenhouse gas emissions will not only make your personal living space more sustainable but it will also save you money in both the short- and long-term. Global warming is occurring more rapidly than it was originally expected to -- only forty years ago, the big worry was global cooling. Even if you remain a cynic, however, and disagree with the consensus of scientists, you will benefit from reduced pollution, a more healthful lifestyle and increased savings from enacting these simple activities that will not reduce the quality of your life.

Get educated.

Educate yourself about global warming. The more facts that you have as to what mainstream science says about it, the more you can persuade others to make simple yet effective changes in daily behavior. Energy-saving techniques either are initially expensive (for example, solar power) or take extra time (for example, recycling), so many people need to be convinced that their efforts matter. Always keep in mind that you are aiming to demonstrate the benefits of these activities and highlight how each person can play a vital role in helping to reduce global warming. Remember that "civil society does not respond at all well to moralistic scolding." Use education to enlighten, not frighten.

But now I will do something about it. I pledge.

I will use CFLs, not incandescent bulbs.

I will set the AC to 25, not 22.

I will take a train or bus instead of a car.

I will use less energy that heats up the earth.

I will use bicycle always for short distance

Global Warming: Is making carbon 'SAFE' the answer?

Mandating fossil fuel producers to sequester (bury) a steadily increasing fraction of the carbon they extract would be a simple, effective, and fair way of sharing out the pain of reducing greenhouse gas emissions, according to a leading group of climate researchers.

Urban 'green' spaces may contribute to global warming

Dispelling the notion that urban "green" spaces help counteract greenhouse gas emissions, new research has found -- in Southern California at least -- that total emissions would be lower if lawns did not exist.

Global warming increases flood risk in mountain areas

The world's mountainous regions are home to about 800 million people and the source of some of the world's major rivers. In these regions, runoff is strongly affected by temperature. This suggests that flooding could be quite sensitive to global warming, but there has been some lack of scientific consensus on the effects of temperature variations on floods.

The Future of Extinction of Plants and Wildlife

The last mass extinction of plant and animal species occurred 65 million years ago with the Dinosaurs. In all, five mass extinctions have occurred and scientists believe earth is in the sixth mass extinction. The author of the book “The Sixth Extinction”, Dr. Leakey states that 50% of the earth’s species will vanish within 100 years. The world as it is now is threatened, including people, who are responsible for earth’s deterioration.

The Damaged Earth
Pesticides contaminate water; overharvesting of animals and plants; air pollution; illegal fishing and the clearing of land are direct results of urbanization and deforestation. People have altered and/or damaged almost half of earth’s land, a very unsustainable rate.
Global warming is having a serious impact as well. A six-degree Celsius increase in global temperature killed 95% of all species on Earth 251 million years ago. An increase of six-degrees Celsius is forecast this century if a change is not made to reverse the damage done to earth. Home sapiens (people) will be one of the 95% of species lost. Noticeable changes of global warming include migration acceleration and the timing of seasons is changing. Migrating birds are migrating earlier, which in turn is causing them to hatch eggs and bear young earlier than they did at the beginning of this century.

Considerations
While this is just the tip of the iceberg, many, many issues need addressing regarding the extinction of plant and animal species. It is more important now than ever before to pull heads out of the sand and make a change for the better to earth. Future generations are threatened, as they are a species as well. This is a much bigger problem than just deciding to recycle plastic, as many believe. If you want to leave a legacy to your future generations, get involved in a program to save the planet. Whether it is on a personal level or a global level, find out what areas need help and what you can do to help.

The issue of global warming

The above scenario is not science fiction but a reality which global warming could cause. Global warming is the increase in the temperature of the earth’s atmosphere caused by greenhouse gases like water vapor, carbon dioxide, methane and ozone. There has been growing awareness and concern among people about this phenomenon. It has become a global issue although it is hotly debated in international circles. It has a fair share of supporters and critics. Its proponents warn that if immediate preventive steps are not taken it will have a disastrous effect on future humankind. Its detractors argue that the problem is grossly overestimated and nothing should be done. They also argue that the steps to tackle the problem will hinder economic progress.