what is global warming and its causes?

Question

I need specific answers. Like how do you know we are experiencing global warming right now?

what are green houses??? I keep eharing that tem but I'm not actually sure what dat is...is it found in our ozone layer or is it a solid mass here on earth?

Answer 1

mild_wild_one:

"The prevailing view among scientists is that global climate change may prove beneficial to many farmers and foresters -- at least in the short term. The logic is straightforward: Plants need atmospheric carbon dioxide to produce food, and by emitting more CO2 into the air, our cars and factories create new sources of plant nutrition that will cause some crops and trees to grow bigger and faster.

But an unprecedented three-year experiment conducted at Stanford University is raising questions about that long-held assumption. Writing in the journal Science, researchers concluded that elevated atmospheric CO2 actually reduces plant growth when combined with other likely consequences of climate change -- namely, higher temperatures, increased precipitation or increased nitrogen deposits in the soil.

The results of the study may prompt researchers and policymakers to rethink one of the standard arguments against taking action to prevent global warming: that natural ecosystems will minimize the problem of fossil fuel emissions by transferring large amounts of carbon in the atmosphere to plants and soils.

"Perhaps we won't get as much help with the carbon problem as we thought we could, and we will need to put more emphasis on both managing vegetation and reducing emissions," said Harold A. Mooney, the Paul S. Achilles Professor of Environmental Biology at Stanford and co-author of the Dec. 6 Science study"
http://news-service.stanford.edu/pr/02/jasperplots124.html

If only co2 levels rise then there will be a beneficial effect. However, the other three main climate change factors -higher temperatures, increased precipitation or increased nitrogen deposits in the soil- will alter this effect.

Answer 2

"Greenhouse gases" refers to the similarity with greenhouses where you can grow vegetables and other plants. You use it to trap the heat from the sun, keep the cold out and make the climate for the plants better.

Greenhouse gases acts just like that around our globe. There are natural greenhouse gases in our atmosphere. Without them the temperature would be about 32 C colder on earth. What we do right now is that we add on to these greenhouse gases, thus making the "greenhouse effect" on earth stronger.

Temperatures is measured around the world and the global trend is upwards. We can also see signs like melting ice around the poles and on our glaciers. Actually, they are melting faster than what most scientists has predicted and it's really worrying.

Answer 3

global warming means that the average temperature rises form year to year. This measure is done only since a few years in relation human existence. Well known scientist think this always happens between ice age and "normal" climate periodical. A further reason might be too many humans on this planet. If you want to see more just ask.

Answer 4

I'm a Russian, hope my English isn't too bad.

Carbon dioxide, the main greenhouse gas, helps grow vegetables and other plants, as greenhouses do.

Don't worry much about global warming. If it mostly man-made, as environmentalists say, we are lucky to have such helpful side-effect of our activities.
Do you know, that carbon dioxide concentration in the atmosphere is very low. I was always astonished how plants could exist with such low concentration of all-important for them carbon dioxide. Later I've found out, that the plants actually were close to their survival limit of carbon dioxide concentration. Now they are feeling better. And carbon dioxide (CO2) concentration is still close to zero. Even if it rise several times, it is still close to zero.

There were warm and cold periods in recent Earth history. Warm periods were also damper ones. Which means less deserts, less ice, more green, more life.

For billions of years, carbon was eventually withdrawn from the constant flow of life, forming deposits of fossil fuels. Volcanoes sometimes added it to the atmosphere. But anyway it's pre-industrial concentration was close to critical limit. So our CO2 emission saves our beloved Earth from desertification, and, in general, helps life.

UPDATE
2 Anders:
The results of the experiment you mentioned, should depend greatly on the initial conditions.

For example, if you set the initial temperature to 35 C, and rise it by 5 C, some plants could experience oppression. But almost all dubious climate change prediction computer models show us, that the colder an area now, the greater temperature rise will occur there. Or, the hotter an area, the smaller temperature rise. The same conclusion comes out from paleontology data.

About fixed nitrogen. Recently I've read an article about it (it's in Russian). The vast majority of soils experience shortage of fixed nitrogen. The problem is well known at least from the beginning of the XX century. That's why nitrogen fertilizers became such popular since the very time of the beginning of their production. Fixed nitrogen, which we emit, helps plants grow as well. But, we can create such conditions, that additional nitrogen would harm plants (doesn't matter that such conditions are extremely uncommon in nature).

About increased precipitation. Look at Amazon basin, or at any other areas with very high precipitation. Flora in that areas seem to be the most thriving in all the world.

So, the article you mentioned, sounds to me like a half-truth, which is worse than a lie.

Answer 5

Some gases ("greenhouse gases") let sunlight in, which warms the Earth, and then block that heat from leaving. That's the "greenhouse effect", and it's a natural thing, mostly caused by water vapor.

Man is making excessive amounts of greenhouse gases, mostly by burning fossil fuels. That causes the delicate natural balance to go out of whack and the Earth warms. That's global warming.

It won't be a Hollywood style disaster. Gradually coastal areas will flood and agriculture will be damaged. But it will be very bad. Rich countries will cope, but it will take huge amounts of money. In poor countries many people will die of starvation, but not all of them.

Most scientists say, in 20-50 years. But we need to start right now to fix it, fixing it will take even longer than that.

More information here:

http://profend.com/global-warming/

Lots of numerical scientific data proving it real here:

http://en.wikipedia.org/wiki/Image:Climate_Change_Attribution.png
http://www.ipcc.ch/SPM2feb07.pdf

Answer 6

Global Warming is being caused by the build up of Green house gases in the atmosphere that trap the heat from the sun.
We know that we are suffering from global warming because of the increase in temperature and the fact that the ice in Antarctica is melting.
there are 4 greenhouse gases : methane, carbon dioxide, nitrous oxide and ozone.
If you need anymore just ask.

Answer 7

It is a bunch of junk science that has caused a hysteria. It is being fueled by people who want to destroy the economies of the US and Britain. It was global cooling in the '70's.

Answer 8

Wow! Anna didn't even list Water Vapor as a greenhouse gas. That is truely scary considering that water vapor is the cause of at least 75% of the greenhouse effect.

Answer 9

The only way to know if we are warming now is for someone to tell you. Temps have increased 1 deg over the last 100 years. You cannot detect a change of just 0.01 Deg.

Answer 10

that is why we need more space like mars?
//// bernhard //// right?