Physics for Everyone: Why Global Warming is Scary
Global Warming – a phrase that is so misunderstood, that scientists trying to push for legislation to stop it, and searching for solutions to this very VERY big problem, have even switched to using the phrase “Climate Change” in attempt to better sway the masses. And while “Climate Change” is accurate, “Global Warming” is also accurate, and really, to me, much, much scarier. Why? Basic physics.
The reason this term is misunderstood, or misbelieved, is Winters like this one (2013-2014), where we are experiencing extreme lows throughout the country, with below freezing weather striking as far South as Georgia. But this is a regional phenomenon. Global Warming is a GLOBAL reality. And given that our global weather is far from homogenous (thank goodness), and ever shifting, it should be little wonder that there will be dips experienced. But, let’s put the phenomenon in easier to understand terms.
We’ve all taken a bath. And we’ve all been in that bath when one end is cold, and the other hot, especially when we’ve been in there a while, and the water’s gone tepid, so we run some more hot water into the tub to heat it up. When we add the hot water, we’re increasing the tub’s average temperature, but we still have a lower temperature on one end of the tub – If we were an ant only experiencing the cooler end of the tub, and someone put an ice cube there, we’d think this Tub Warming phenomenon was hooey – clearly it just got colder! But overall, it’s not – we just aren’t experiencing it in our neck of the woods. Now, a tub is a small, simple system, and the planet is a ginormous, complicated one – so these variations are going to be much more pronounced on a world-wide scale.
There is pretty much a consensus amongst the scientific community, across a multitude of disciplines, that the average global temperature has been on the rise since the 19th Century. It in fact has risen by 0.85 degrees Celsius (1) (2). That doesn’t sound like much, but let’s do a little bit of math to put it into perspective (I usually try to avoid math in these articles to keep them as simple as possible, but sometimes nothing brings a thing into harsh clarity than simple figures, which is why physics is so math-heavy).
Some of the most profound physical truths can be revealed with simple mathematical formulae and this is one of them. Since less than a degree Celsius seems like such a small temperature increase, we need to figure out how to understand what that really means, and why it’s a big deal – why scientists are up in arms about it. Well, it boils down to energy. For day-to-day usage, we tend to think of Temperature as something that just means how comfortable we are. But to a physicist, it’s much, much more. It’s not just some random figure – it’s the tendency of one object to give up heat to another object. And heat is energy flow. The hotter the temperature, the more heat it wants to give up, the more energy is flowing from one area to another. So a rise in the planet’s average temperature means energy has been added to the atmosphere.
We have a very simple formula for this. It involves the mass of the atmosphere (everything has mass, even air), its specific heat capacity (or the amount of energy necessary to raise the temperature of a given amount of matter by 1 degree Celsius), and the temperature increase. We have the following formula for Heat:
Where H represents heat (or the energy flow), m is mass, C is the specific heat Capacity, and T is temperature. We know, from the repeatedly cross-checked calculations of many, many scientists, that the atmosphere has a mass of 5.1 * 10^18 Kg (that’s a LOT of air – that little carat means 10 raised to the 18th power, or a 1 with 18 zeroes behind it). Its specific heat capacity is 1,005 Joules/Kg/Degree Kelvin (scientists like working in Degrees Kelvin instead of Fahrenheit or Celsius because the base point is the absolute coldest anything could ever possibly get – but, conveniently, 1 degree Celsius is equal to 1 degree Kelvin). And for T, we’re going to use our change of 0.85 K. So we have:
H=5.1*10^18 Kg * 1005 J/Kg/K * 0.85 K
H= 4.36 *10^21 Joules.
Hrm. That’s not very intuitive, is it? We don’t use Joules in our daily life. But it sure does seem like a REALLY big number. Since it seems big, let’s get a grasp on it by using something similarly big.
Tsar Bomba was the largest nuclear bomb ever detonated, weighing in with a detonation that yielded about 50 Megatons of TNT worth of energy. In Joules, that comes to 50*4.184*10^15= 2.09*10^17 Joules. Significantly LESS than the energy the atmosphere has gained since 1880.
How much less? Let’s divide and find out. When we do, we find out that the increase in global average temperature is an indication that our atmosphere has absorbed an amount of energy equivalent to the detonation of 20,813 Tsar Bombas. Holy cow. Scared yet? You should be. This is why scientists are clamouring about global warming.
Remember, this is HEAT. I chose that particular formula because it gave us heat, which isn’t just energy sitting still and doing nothing. The air hasn’t just absorbed energy and gotten warmer. Like I said earlier, heat is energy FLOW. That energy is moving. It’s doing things. LOTS of things. It’s causing turbulence, causing air to rush around, to move from one part of the planet to the other. In short, it’s causing weather patterns to shift, to become more extreme, and to become more energetic – more violent. We’re seeing this more and more the past few years as storms seem to become bigger, more frequent, and more devastating.
And worse, the temperature is projected to go up even HIGHER in the next century, with some conservative estimates showing a further increase of 4 degrees Celsius, and others as high as 8 degrees Celsius. (3) That’ll be like detonating 980,019 MORE Tsar Bombas in our atmosphere on the low end, TWICE that with the higher estimates! If you think the weather’s crazy now, just wait. It’s going to get worse.
I’ll save the why’s of the increase for later. For now, I’ll leave you with the facts I just dropped, the math, and let you think about it.