We know that climates have changed in the past and it is only fair to assume that climates will change in the future. We also know that there are many factors that affect the climate but to stay on topic we know that without greenhouse gases the average temperature on earth would 34C cooler then it is today. (Earth would be a giant snowball)

We know that CO2 is one of those greenhouse gases and that mankind has increased the levels of CO2 in the atmosphere by 40% (as a result of dumping the waste products from burning fossil fuels for energy into the atmosphere) And if everything else remains the same this additional CO2 will increase the heat retention capacity of the atmosphere. Scientist are trying to find out what else has affected and might affect the heat retention capacity over the medium to long term and for lack of another earth to experiment on, they try to use proxies to find out past climates and use computer models to predict the effects of feedback mechanisms (positive and negative) of future climates.

As for the reasons why we would want to do this; It should be obvious that when sea levels rise or fall, it affects where we live and infrastructure like harbors and cities. Climate change will effect food production and economics on a wider scale. And t does not matter if you subscribe to communism, capitalism (or something in between) as the best way to organize our economy, it is smart to try and predict future trends regardless if you are motivated by money or compassion.

Then again deniers will have us sitting around the camp fire singing Kumbaya instead of finding out how the natural world works and how we affect it and leaving it to future generations to clean up the mess.

Edit:

The video's young earth creationist Maxx posted, have been debunked by the scientist featuring in them. [1]

All the graphs and charts can be cooked by those with a political agenda. For the most part, the left assaults counter opinions with ad Hominem attacks, name calling. The left that pushes this hoax, and it is a hoax, uses slimy politicians like Al Gore, long bony finger liars like Bill Clinton, and misplaced Kenyans like Hussein Obama to further their cause.

I've been following the leftist hucksters pushing the man made climate change hoax for about 40 years. First they proclaimed that Global Cooling was an absolute truth. Then, a little more than 30 years ago they changed to Global Warming. They said that the sea level in areas along the west coast where I live would rise, and that within 10 years there would be a marked difference, and that in 20 years the ocean would invade coastal towns and cities that were of lower elevations.

Well, it's been 30 years and nothing has changed. That's right, the mean ocean level is the same and the mean ocean temperature is the same as its always been. I live within walking distance, less than a half mile from 8 miles of white sandy beach, and I have lived here since 1976. The ocean is so close to the highway at this point, that during a strong storm the ocean throws driftwood on the road. If their lies were true, the ocean and the town should be underwater by now. Part of the town is about 6 feet above sea level, and nothing has changed.

I've been interested in Climate Change because of the threat since I live here. Also,I have a minor in Earth Science so I know a little about the earth.

It's difficult to measure climate because one must select areas of the earth to take measurements, and they don't come out the same way. So, if the ocean is rising like they said it would 30 years ago, then show me! It doesn't take a climate scientist to see the truth.

Your question asks about climate change but then you compare it to predicting next month's weather. Weather and climate are two different things. No climatologist would say that it was or would be such-and-such a temperature at a particular time on a particular date. That's the province of weather forecasting (or recording).

As for how we know about past climates, that gets interesting. When we have tropical plants growing in Antarctica, we can either surmise that either Antarctica was in the tropics or that the climate was a great deal warmer then than it is now. If those plants are all over the globe at the same time, it is certain that the Earth was a lot warmer then. We can determine the vegetation either from plant fossils or from analysis of pollen in sediments. Yes, some people can identify the plant from just a grain of pollen.

From all this, we can tell that the climate has fluctuated in the past. Sometimes glaciers covered large portions of the globe and sea levels were low because of all the water locked up in the ice. At other times, temperatures were high, with very little ice. At those times, sea levels were higher. The central portion of North America was once a shallow sea. I don't know of anyone who wants to return to that. What is unique about present conditions is the RATE of change. We get measurable increases in global temperatures over a period of decades or centuries, not over millenia. What is the difference? Humans are around now. The simplest explanation that covers all the available data is that humans are responsible for the large rate of increase. All the obfuscation and spin-doctoring from those in the pay of Big Energy cannot change that.

And, no, your questions do not sound dumb. The dumb thing to do is not to question.

It certainly does seen that the earth is becoming hotter. Massive amounts of cars and high density living would help this, but so does nature. The biblical story of the flood that covered the earth is certainly a tall story- just like the Harry Potter stories. Fantasy- but a certain element of truth. It is geologically proven that over the billions of years on this earth, there have been ice ages followed by global warning. And yes there have always been severe floods and droughts. So to answer your question, global warning is both man made and nature made. Sorry to ramble, but this is the best i can offer

It has happened in the past; look at the Ice Ages. Here's the problem: we know what caused the ice ages--earths axis is like a top and will wobble, the rotation around the sun will become extremely unsymmetrical, both happen over hundreds of thousands of years. We've nearly tripled our earths population in a matter of 50 years; that's 3 times as many people who are trying to live in this time of development full of CO2 emitting machines--sorry, but CO2 and the global temperature reflect each other almost perfectly, so don't try and say it doesn't. Our ice caps are one of the most important features: when the sun hits the ice, it reflect nearly 90% of all the energy, but since our ice caps are melting, that's more space filled with dark soil and water now absorbing 90% of the energy. In the last 5-10 years we've nearly tripled the melting of our old ice in the arctic (older than 9 years); meaning that, yes, we will still get more ice due to seasons, but it'll be very thin since it's only been there a few years--easier melting. If you look at Greenland, there are now lakes pooling atop of the ice; that water absorbs the heat, melting the ice beneath it. Eventually the water will want to find lower ground so it'll create a stream or river to do so; if you follow it it will eventually stop. When it disappears or stops, that's where it found its way down; it'll go all the way down to the bottom, lubricating it causing ice to break off at a mind boggling rate. As this happens, the ice up stream will begin to crack and deform; as it cracks, it begins to collect water absorbing heat, and since it's heavier than ice, it will begin to hydro fracture its way down the ice sheet accelerating the process. There's about 22 ft of sea level rise in Greenland, and nearly 9 times that in Antarctica. We've already lost a great deal of ice, but why hasn't it created a noticeable sea level rise? Because it's the ice that is floating, so it's like ice cubes in a glass of water; when it melts it doesn't cause the glass to over flow, it just creates an equilibrium between the two--give it time as the ice above the sea melts. Since we've doubled to speed of Greenlands melting and 2012 was the smallest the Arctic has been, we've pushed ourselves 50 years ahead of the worst case scenario scientists were predicting 7-8 years ago. This is only part of a GLOBAL issue.

Maxx: you lost your credibility a long time ago. If you're only getting your information from 2 videos, you shouldn't be on here.

You'd like to know what other people think. OK. You can ask the yahoos on Yahoo. But wouldn't it be great if there was a place that all of America's greatest scientists came together to explain complex science? Actually, there is such an organization. It's the National Academy of Science. It was created by the signature of Abraham Lincoln in order to advise Congress and the nation on science. It is the association of America's greatest scientists. America's greatest scientists have created a booklet that explains exactly what you are looking for.

If you want an answer in a sentence or paragraph, forgetaboutit. If you want to read 30 pages for your own education, then go to the NAS. Here's a link to the page with the booklet.

http://nas-sites.org/americasclimatechoi...

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Here you can see what complete rubbish the videos Maxx posted are: