CAUSES OF GLOBAL WARMING

What Causes Global Warming?

Scientists have spent decades figuring out what is causing global warming. They've looked at the natural cycles and events that are known to influence climate. But the amount and pattern of warming that's been measured can't be explained by these factors alone. The only way to explain the pattern is to include the effect of greenhouse gases (GHGs) emitted by humans.

To bring all this information together, the United Nations formed a group of scientists called the International Panel on Climate Change, or IPCC. The IPCC meets every few years to review the latest scientific findings and write a report summarizing all that is known about global warming. Each report represents a consensus, or agreement, among hundreds of leading scientists.

One of the first things scientists learned is that there are several greenhouse gases responsible for warming, and humans emit them in a variety of ways. Most come from the combustion of fossil fuels in cars, factories and electricity production. The gas responsible for the most warming is carbon dioxide, also called CO2. Other contributors include methane released from landfills and agriculture (especially from the digestive systems of grazing animals), nitrous oxide from fertilizers, gases used for refrigeration and industrial processes, and the loss of forests that would otherwise store CO2.

Different greenhouse gases have very different heat-trapping abilities. Some of them can even trap more heat than CO2. A molecule of methane produces more than 20 times the warming of a molecule of CO2. Nitrous oxide is 300 times more powerful than CO2. Other gases, such as chlorofluorocarbons (which have been banned in much of the world because they also degrade the ozone layer), have heat-trapping potential thousands of times greater than CO2. But because their concentrations are much lower than CO2, none of these gases adds as much warmth to the atmosphere as CO2 does.

WHAT IS GLOBAL WARMING?

WHAT IS GLOBAL WARMING?

Global warming is the next big impact that will bring about a change in the weather patterns. By definition, Global Warming is the increase in average temperature that gradually warms the Earth’s atmosphere. It is a phenomenon, which has been on the rise but in the last century, the increase in the levels have been alarming.

The average temperature of the atmosphere has risen by 0.74 - 0.18 °C during the last century. According to the study by the Intergovernmental Panel on Climate Change (IPCC), it is observed that the increase in global average temperature has been caused due to an increase in greenhouse gas concentrations. This has led to an unprecedented warming of the Earth’s surface.

The other phenomena’s responsible for global warming include volcanoes and solar variations. Base on some of the models by the IPCC, the prediction is that the global temperature is likely to rise by 1.1 to 6.4 °C between 1990 and 2100. This increase in temperature will cause climatic changes and extreme weather conditions like rising sea level, change in the amount of precipitation, above average rainfall, melting of polar ice caps and glaciers, storms and hurricanes.

On the worse side, it will also affect yield of crops as well as plants and animals leading to extinction of different species. Global warming will increase the spread of diseases and there will be droughts and flooding, coral reef bleaching and forest fires. Global warming is no more a myth but a fast approaching reality, which in the long term will bring the much feared ice age that will wipe out all living organism on Earth.

OTHER DEFINITION:

• The Planet Is Heating Up—and Fast

Glaciers are melting, sea levels are rising, cloud forests are drying, and wildlife is scrambling to keep pace. It's becoming clear that humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.

We call the result global warming, but it is causing a set of changes to the Earth's climate, or long-term weather patterns, that varies from place to place. As the Earth spins each day, the new heat swirls with it, picking up moisture over the oceans, rising here, settling there. It's changing the rhythms of climate that all living things have come to rely upon.

What will we do to slow this warming? How will we cope with the changes we've already set into motion? While we struggle to figure it all out, the face of the Earth as we know it—coasts, forests, farms and snow-capped mountains—hangs in the balance.

• What is global warming?

This is a fair question, as much written and said about “global warming”. The term is often misused and people tend ask questions like, 'do you believe in global warming?' This is a bit like someone asking an economist, whether they believe in inflation. It is difficult to know where to start when answering, What is Global Warming? This is because there are other hidden questions buried in the original one. Many people when asking the first question, are often also wanting to know if the warming is attributed to human activity are greenhouse gases building up in the atmosphere?; and is the warming something they should be concerned about? The short answer to all those questions is YES! Climate change has become a big political issue and a great deal of debate continues about the solutions. One approach being considered to reduce global carbon emissions is the idea of contraction and convergence. Under this approach all countries would participate in a global emission reduction with quantified emission targets.