How Life alters Climate

People had long speculated that the climate might be altered where forests were cut down,marshes drained or land irrigated. Scientists were skeptical. During the first half of the 20th century, they studied climate as a system of echanical physics and mineral chemistry, churning along heedless of the planet’s thin film of living organisms. Then around 1960, evidence of a rise in carbon dioxide showed that at least one species, could indeed alter global climate—humanity. As scientists looked more deeply into how carbon moved in and out of the atmosphere, they discovered many ways that other organisms could also exert powerful influences. Forests in particular were deeply involved in the carbon cycle, and from the 1970s onward, scientists argued over just what deforestation might mean for climate. By the 1980s, it was certain that all the planet’s ecosystems were major players in the climate changes that would determine their own future.

Modern Temperature Trend

Tracking the world’s average temperature from the late 19th century, people in the 1930s realized there had been a pronounced warming trend. During the 1960s, weather experts found that over the past couple of decades the trend had shifted to cooling. With a new awareness that climate could change in serious ways, many scientists predicted a continued cooling, perhaps a phase of a long natural cycle or perhaps caused by human pollution of the atmosphere with smog and dust. Others insisted that the effects of such pollution were temporary, and humanity’s emission of greenhouse gases would bring warming over the long run. This group’s views became predominant in the late 1970s. As global warming resumed it became clear that the cooling spell (mainly a Northern Hemisphere effect) had indeed been a temporary distraction. When the rise continued into the 21st century with unprecedented scope, scientists recognized that it signaled a profound change in the climate system.

Spots are spotted in the Sun

Our sun has spots ! These spots appear dark in photographs like below but in fact, sunspots are quite bright,they are just dark compared to the rest of the sun. Sunspots areabout the size of the earth and frequently occur in groups.Sunspots Occur when a concentrated portion of solar magnetic field pokes through the surface.

Spots on the sun surface

Changing Sun, so the Climate?

Since it is the Sun’s energy that drives the weather system, scientists naturally wondered whether they might connect climate changes with solar variations. Yet the Sun seemed to be stable over the timescale of human lifetimes. Attempts to discover cyclic variations in weather and connect them with the 11-year sunspot cycle, or other possible solar cycles ranging up to a few centuries long, gave results that were ambiguous at best. These attempts got a well-deserved bad reputation. Jack Eddy overcame this with a 1976 study that demonstrated that irregular variations in solar surface activity, a few centuries long, were connected with major climate shifts. The mechanism remained uncertain, but plausible candidates emerged. The next crucial question was whether a rise in the Sun’s activity could explain the global warming seen in the 20th century? By the 1990s, there was a tentative answer: minor solar variations could indeed have been partly responsible for some past fluctuations… but future warming from the rise in
greenhouse gases would far outweigh any solar effects.

Ice Sheets and Rising Seas

A big enough rise of global temperatures would eventually melt the world’s glaciers, and indeed a retreat of mountain glaciers since the 19th century was apparent in some regions. That would release enough water to raise the sea level a bit. Worse, beginning in the 1960s, several glacier experts warned that part of the Antarctic ice sheet seemed unstable. If the huge mass slid into the ocean, the rise of sea level would wreak great harm, perhaps within the next century or two. While that seemed unlikely (although not impossible), by the 1980s scientists realized that global
warming would probably raise sea level enough to damage populous coastal regions

Impacts of Global Warming

What do we know about the impacts of global warming?

A large body of scientificstudies, exhaustively reviewed, has produced a long list of possibilities. Nobody can say that any of the items on the list are certain to happen. But all the world’s climate experts, virtually without dissent, agree that the impacts listed below are more likely than not to happen. For some items, the probabilities range up to almost certain.

The following are the likely consequences of warming by a few degrees Celsius—that is, what we may expect if humanity manages to begin restraining its emissions soon, so that greenhouse well before the end of this century. By 2007, many of the predicted changes were observed to be actually happening 

* Most places will continue to get warmer, especially at night and in winter. The temperature change will benefit some regions while harming others—for example, patterns of tourism will shift. The warmer winters will improve health and agriculture in some areas, but globally, mortality will rise and food supplies will be endangered due to more frequent and extreme summer heat waves and other effects. Regions not directly harmed will suffer indirectly from higher food prices and a press of refugees from afflicted regions.

* Sea levels will continue to rise for many centuries. The last time the planet was 3°C warmer than now, the sea level as roughly 5 meters higher. That submerged coastlines where many millions of people now live, including cities from New York to Shanghai. The rise will probably be so gradual that later generations can simply abandon their parents’ homes, but a ruinously swift rise cannot be entirely ruled out. Meanwhile storm surges will cause emergencies.

 * Weather patterns will keep changing toward an intensified water cycle with stronger floods and droughts. Most regions now subject to droughts will probably get drier (because of warmth as well as less precipitation), and most wet regions will get wetter. Extreme weather events will become more frequent and worse. In particular, storms with more intense rainfall are liable to bring worse floods. Mountain glaciers and winter snowpack will shrink, jeopardizing many water supply systems. Each of these things has already begun to happen in some regions.

* Ecosystems will be stressed, although some managed agricultural and forestry systems will benefit, at least in the early decades of warming. Uncounted valuable species, especially in the Arctic, mountain areas, and tropical seas, must shift their ranges. Many that cannot will face extinction. A variety of pests and tropical diseases are expected to spread to warmed regions. Each of these problems has already been observed in numerous places.

 

* Increased carbon dioxide levels will affect biological systems independent of climate change. Some crops will be fertilized, as will some invasive weeds (the balance of benefit vs. harm is uncertain). The oceans will continue to become markedly more acidic, gravely endangering coral reefs, and probably harming fisheries and other marine life.

 * There will be significant unforeseen impacts. Most of these will probably be harmful, since human and natural systems are well adapted to the present climate.

 

The climate system and ecosystems are complex and only partly understood, so there is a chance that the impacts will not be as bad as predicted. There is a similar chance of impacts grievously worse than predicted. If the CO₂ level keeps rising to well beyond twice the pre-industrial level along with a rise of other greenhouse gases, as must inevitably happen if we do not take strong action soon, the results will certainly be worse—probably including a radical reorganization and impoverishment of many of the ecosystems that sustain our civilization.

Protect Nature

Hi,

I am writing this in line up with my previous post of Global Warming.This day is a significant one for our thinking about climate change , with the latest British Government notice now suggesting that average summer temperature in the UK will increase by as much as 6C,with peaks in London over 40C. These changes will have an enormous impact on our wildlife. Parts of our green and pleasant land could become dry and dusty within decades and some of our native species will face a major struggle for survival. A few animals like capercaillie, mountain ringlet or mountain hare are facing extinction if climate change takes hold in the way thats is predicted.But most wildlife will adopt to the climate if we help it by improving habitate in step with the climate.

Together land and oceans absorb half os all all green house gas emissions. Urban green spaces help cool built-up areas by upto 4C and better protected upland rivers can increaase the supply of fresh drinking water. Conserving a healthy natural environment is therefore not only morrally correct, it is also cost -effective action preparing our globe for the effects of global warming. Viewed in this light we are ill prepared for the challenges ahead.we have put  in place some spectacularly high hurdles in the way of our ability to respond to environmental challenge.

Protecting and working with nature makes economic sense and can be done now. Continuing to rely on undeveloped technologies as a safety net for climate change would be a disaster.

 

By

Livz

Global warming

Dear all, a little note on global warming

Global warming has been a major problem for the past 50 years, Gases like carbon dioxide , nitrous oxide and methane that make our lives possible seem to threaten our very existance.Of these, the emission of carbon dioxide is the main cause for global warming.Forests play a key role in the ecological system.It is the trees and plants which inhale carbon dioxide and release oxygen and thus re create the quality of air we breathe.

It is easy for to cut down a tree, but not so to grow one. we burn fossil fuels, resulting in the release of plenty of carbon dioxide. Many of us still dont know its ill-effects.Many developed nations seem hesitant to take drastic steps to reduce the greenhouse gas emissions.Many a meeting aimed at doing so has failed because of this attitude.

I feel, the extreme high temperature is because of this global warming. If u got to blame on some one, that could be you.We march ahead with the development of new technolgy and methodology at the cost of some precious things ,endangering.

by

Joellivz

The Solution

hi…

Lets start solving…the Unanswered…..