https://en.wikipedia.org/wiki/Global_warming https://en.wikipedia.org/wiki/Global_warming covers much of that. 1. Humans pollute. One form of pollution is exha

https://en.wikipedia.org/wiki/Global_warming https://en.wikipedia.org/wiki/Global_warming covers much of that. 1. Humans pollute. One form of pollution is exhaust gases. We burn a lot of fossil fuels. One of the resulting gasses is CO2 - carbon dioxide. This ends up in the atmosphere. CO2 is naturally present in the atmosphere. However, we are putting CO2 into the atmosphere faster than it can be taken out. One reason is that fossil fuels are a form of long-term storage, which took CO2 out of the ecosystem across a long period of time. We are returning that CO2 at a much faster rate than it was created. CO2 is a "greenhouse gas." It acts as an insulator for infrared energy, a.k.a, "heat". Light comes to the earth from the Sun, warms up the planet, and is re-radiated back into space. This includes a shift from visible to infrared energy. CO2 blocks infrared more than it does visible, so adding CO2 to the atmosphere can result in more heat. (The mechanics are very complicated. Clouds reflect light, so lower energy. The oceans absorb CO2 but become more acidic.) The amount of CO2 in the air is small. It's measured in parts per million, or "ppm". The "400 ppm" is a semi-symbolic threshold which indicates the severity of the problem. It's been over a million years since the CO2 levels were his high, meaning (roughly) that insulation level is this high, meaning (roughly) that it's going to get hotter. 2. https://en.wikipedia.org/wiki/Effects_of_global_warming https://en.wikipedia.org/wiki/Effects_of_global_warming gives a good summary of the effects of global warming. 3. I cannot answer this one. There are a myriad of possibilities. > I also don't mean this to come across as lazy, I just really don't know what I don't know and I've seen enough convincingly educated comments here to ask. To help pursuade people that you aren't lazy, you could include information about what you've looked at, or why you feel like the Wikipedia pages are insufficiently unbiased. There are many documents referenced from those pages. A search for the IPCC reports includes pointers to things like http://ipcc-wg2.gov/AR5/images/uploads/WG2AR5_SPM_FINAL.pdf http://ipcc-wg2.gov/AR5/images/uploads/WG2AR5_SPM_FINAL.pdf "Climate Change 2014 / Impacts, Adaption, and Vulnerability / Summary for Policymakers".