Upon watching this video you notice a few things. Firstly that Bill Maher is smug, but we already knew that, so ignore him for the purpose of listening to Neil Degrasse Tyson. Also, notice that the guy who believes climate change is fake works for General Motors and is protecting his own interests. It's always good to know when a person's motivations might subvert their ability to filter bullshit.
How it works, basically:
Naturally we'll start with the problem. The overall temperature of the earth is rising. So, as skeptics, the first piece of evidence you would want to see is that the earth actually is warming, before you go into the why.
Since roughly the 1850s, weather stations have been tracking temperatures around the world. They have shown over the past century that the temperature has risen about one degree farenheit, most intensely rising over the past two decades.
Source: New York Times
The four different lines are agencies that report global temperature trends, all pretty much on the same page. One degree doesn't seem like a lot, but the important thing is to note the intensity over the past two decades. Also know that the causes of human induced climate changed are trending up, not down.
Another way that we can know that the earth is warming is from the rising sea levels. The process of thermal expansion, meaning that water expands as it gets warmer, combined with the melting of ice accounts for about half of the global sea level rise.
Proxy records are also a tool for measuring the earth's warming. Proxy records are sophisticated ways of looking back and figuring out what the temperature was over time such as taking ice core samples, tree ring records, and measuring coral reefs. All of these methods are indirect and by definition not as precise or accurate as a direct record, but they all point in the direction of intense warming.
So now that we know for sure that the earth is warming, what is causing it?
Think of the temperature of the earth as a balancing act. It is dependent on the amount of energy entering and leaving the earth. Incoming energy is absorbed by the sun, it warms. The sun's energy is reflected back to space, it doesn't warm. The energy is released back into space, the earth cools. Any change in the reflectivity alters the balance. Any change in the amount of energy we receive from the sun alters the balance.
Also, any changes in the greenhouse effect will alter the balance. The greenhouse effect is when the sun's energy reaches the earth and certain greenhouse gases such as water vapor, carbon dioxide, and methane absorb energy, slowing or preventing the loss of heat to space. Think of the greenhouse effect like a Snuggie keeping the world warmer than it would otherwise be.
Since the industrial revolution in the 1750s, humans have contributed substantially to the amount of carbon dioxide and other heat-trapping gases to the atmosphere. Atmospheric carbon dioxide concentrations have increased almost 40% since pre-industrial times from approximately 280 parts per million by volume (ppmv) in the 18th century to 390 ppmv in 2010. The current level is higher than it has been in at least 800,000 years. (source)
Basically, our Snuggie is growing out of control. Scary thought.
Other than giant analogous Snuggies, what kind of problems can we expect from the earth warming, now that we know it's happening and we're causing it?
It depends on your geographical location and ecosystem. In the south west of the United States droughts will worsen. The south east will likely face sea level rise, increase hurricane intensity, storm surges, growth of crops will be affected.
Super-storm Sandy jacked this dude's house. What say you about that Bob Lutz of general motors?
Bob Lutz's most likely reaction: I dunno, just buy more cars please, do it for the economy.
People in poor countries will suffer the most repercussions initially as they live in the areas most available to exposure and have the least resources to protect themselves. Poor countries that also have some of the lowest emissions and contributed little to the problem.
The next blog will be about some solutions that are being thrown around, and goals that are reasonable to stop the problem.
In case you missed the introduction: A Few Pertinent Thoughts