Honest_Johniii | Posted 12:51 pm, 12/08/2016 |
I'm glad he did, We already had two ice ages and man wasn't there to effect them. I do not believe Al Gore, he has used climate change, which does not exist to make millions of dollars to put in his pocket. I believe the climate will change back and forth hot and cold, I do not think it is caused by man. Way to go Trump. You are right as rain again. |
What you believe is completely irrelevant as for Trump and you talk about being dead wrong.
Allow me to educate you on this. Yes the climate has shifted often in the past its constantly shifting over thousands of years. Why is it not just static? A number of things factor into this elements that can force the climate to shift and the collection of feedback's that act in response to the forcing.
Think of a forcing as a lever something that when changed sets everything into motion. What are those levers then we need to ask.
Keeping this list simple the levers that control the climate system are.
Solar Output
Orbital variation
Axial tilt
Atmospheric composition
planetary albedo
So we understand what can cause the climate to change. We can even calculate changes in overall energy based on shifts in these factors.
So the next question how do we know the planet is warming?
We actually have multiple ways of doing this.
The first is direct temperature readings we take measurements over a long enough period of time and we can determine the trend line. The trend line is what gives us the overall direction up and down and it's important to note that trend lines require measurements over decades. This is required because of things like the el nino cycle. And the trend line shows temperature averages rising on a global scale.
Another method is simple observation. Ice is temperature sensitive if the average is going up we expect more melt if its going down we expect the trend line will result in more freeze to keep things simple. And again with this measurement we see more melt and a trend line going up.
The final method I will mention is a more recent development. We can now measure the planets energy balance. What this means is how much energy is coming into the planet from the sun vs how much energy is being released back into space. If the planet is taking in more energy than is being released back out that shows it is warming up. If it releases more than it is taking in then it is cooling down. And this measurement again shows a positive trend line toward warming.
So we know without a doubt the planet is warming because we have multiple lines of evidence that all reach the same conclusion. So the next step is how do we figure out the cause?
Recall the levers I mentioned before. Well we can measure and account for their contributions.
So we look first at Solar Output, Orbital variation, and Axial tilt. These have historically been the primary drivers. Only we see that they fail to account for the changes we are seeing now so they are not to blame.
That leaves us with Atmospheric composition and planetary albedo. Have we caused some changes in the albedo? Yes and we can measure that influence and it fails to account for the changes we are seeing.
And that leaves us with only one more lever Atmospheric composition. Has that been changing? Yes it has and we have measured and documented those changes. Are the changes enough to account for what we are seeing? Yes once again it accounts perfectly for the observed reality.
So we have found the lever for current changes in the climate system atmospheric composition.
So now the science instantly blames humans right? Wrong because we know a number of things that can cause these changes and those must be accounted for first. So we look at what changes are taking place and see that by far the largest is the increase in CO2 concentrations.
But that alone is still not enough to prove its human caused. First we have to identify and account for all of the natural sources of carbon emissions. Which we have done repeatedly and what we find is more CO2 is entering the atmosphere than natural sources can account for.
At this point we can make a safe assumption that it's probably our activity but we can't say without a doubt it is yet there is one more thing we need to do.
How do we know that the increased C02 is not just the result of some unknown natural source? It might be unlikely but its possible right?
Well as it turns out human emissions have a distinct isotropic signature thanks to the processes involved that sets them apart from natural sources. So if we look at the excess CO2 in the environment we should see that signature and if we don't then it has to be an unknown natural source.
And when we look we find that yes the signature is present the excess CO2 is the result of our activity.
This is how we know beyond all reasonable doubt that the Earth is getting warmer and we are the cause of it.
So then the question becomes is this a problem after all the climate has changed in the past whats the harm right? Natural climate change takes place over thousands of years. The changes we are causing are happening over the course of 100 or so. Such rapid changes are a direct threat to our food and water supplies.