Global Warming Is As Undeniable As Gravity - Here's Why
If you've ever gotten into a car on a sunny day, you know that global warming is real. The inside of the car will be much hotter than the air outside. This is because light energy from the sun gets into the car, and the interior car surfaces absorb this energy, which heats the car's seat, dashboard, floor, etc. The car's roof and windows then trap the heat, and the whole inside of the car gets hotter.
A greenhouse (with walls of glass) or hoop house (with walls of plastic) works on the same principle. Sunlight penetrates the walls, is absorbed by and heats interior surfaces, and the heat radiated by those surfaces is trapped inside. Even in winter, the greenhouse will warm in the sun and can be used to grow food and flowers.
The earth is warm for the same reason a car interior or greenhouse is. The difference is that the heat-trapping planetary "walls" are made of gases in the earth's atmosphere. The gases that are best at trapping heat are called "greenhouse gases."
Without this atmospheric blanket, our planet would be too cold to support life as we know it. Most of the sunlight that hits the earth would just be radiated back into space. So some greenhouse gases are needed to keep earth green and thriving. These are produced by natural forces, and over time fluctuate within limits that have been compatible with life as we know it.
The problem with human-caused warming is that greenhouse gases are produced by human activities in amounts hugely in excess of historical natural ranges. Thus, the heat-trapping atmospheric blanket lets less heat energy escape back into space, and the planet continues to warm. This results in climate change - an alteration in the patterns of temperature, wind, rainfall, and major weather-related events over the planet.
While humans can deny the existence of this process, this doubt does not impact the real world situation. It's like denying gravity, another basic law of physics. No matter how much you say it's not so, pass laws against it, or try to ignore gravity, if you are standing on the earth's surface and toss a ball into the air, it will come back down. Similarly, if heat radiates up into a thickened layer of greenhouse gases, it will be trapped by the atmosphere and contribute to overheating the planet.