Good lord, Al Gore didin't INVENT global warming. Climate change is built on the foundation of thousands of studies by thousands of individual scientists. The first paper that suggested it could be an issue was Svante Arrhenius in 1896 (http://www.rsc.org/images/Arrhenius1896_tcm18-173546.pdf, or hell, you could even extend that to Fourier's 1824 work on the presence of greenhouse gasses that keep the earth's atmosphere warmer)! Many of the laws that point to climate change can be found in any Physics 101 or Chemistry 101 book. However, global warming didn't begin to gain publicity outside of the scientific arena until the 1980s and was certainly an issue before Al Gore made "An inconvenient truth".
One of the biggest issues with AGW is that Earth's hydrological cycle is incredibly complex and requires physical understanding from the micron scale at highfrequencies to centuries. Highlighting some of the complexity of these potential hydrological feedbacks:
Clausius Clapeyron equation (established in the early 19th century), that for each degree celsius the atmosphere warms, the atmosphere can hold 7.6%more water. Now water vapor is a also major greenhouse gas! Water vapor is natural, but when our increases in anthropogenic GHGs, water vapor can amplify the effects of small change in greenhouse gasses.
We should worry about the hydrological cycle getting really involved with climate change because Earth's population is more dependent on Earth's resources than ever before. With about 7 billion people looking to live a higher quality life, stable resources are highly important. If you begin to f*ck with earth's energy balance, there will be consequences. We've built our landscapes expecting climatic conditions to be fairly constant, but if farmlands become to arid to farm, or if the stromsurge-sea level rise combo regularly bursts on up into your bustling metropolis, etc etc, enormous amounts of time and money will have to be spent to rearrange everything to best fit into these new norms. Alternatively, we can focus on finding and using more eco-friendly fuel sources to replace a fuel source that already has a limited lifetime.