earth climate - rate of change

Sunday March 26, 2017

When someone says do not engage troll on the internet, they are probably right. Don’t do it. To quote AstroKatie, “Twitter debates/disagreements can absolutely be productive but only if you have time and reason to believe other party engaging in good faith”.

I just engaged someone (a complete stranger) and I hope I will not regret my decision. The topic is about climate change. I am pro-papers, meaning that I frequently go back to the published, peer-reviewed papers whenever possible. I do not engage with secondary news articles that probably over-summarize, under- or over-state the actual figures, and possibly leaving out other scientific assumptions that might be proven fatal if we don’t talk about that. I must also admit that I am not a person well-versed with climate data, jargons, and their specific scientific interpretations. However, I have been trained in the scientific enterprise, meaning that I can analyze the data to understand the context that specific data belongs to.

So what is the issue?

“But who is to say it would not have done that even without humans on the earth. There is not a single climate model that has accurately predicted the climate, even short term. When they can use the data gathered with no change, and predict the climate, then I might believe it. But if you look at temperatures over millions of years, you will find we are actually in a cool period of the earths climate.”

I cannot comment on the first three sentences, but I can provide some valuable insight on the last sentence. Glen Fergus provided a timeline of earth temperature since almost the beginning of time till our modern time. The timeline is accessible on Wikipedia: geologic temperature record.

all paleotemps

People often argue “do not refer to Wikipedia”, I would argue “yes you can if there is/are source(s) included”. Glen did his homework after analyzing almost twelve papers and two other sources, so this chart should be a sound data.

It is true that we are in the cold region. However, we can’t assume the earth we see today is the same like it was, say, 10-500 million years ago. Let’s put this into a proper context. Modern human (Homo sapiens) has existed on earth about 195,000 years ago as archeologic data suggests. So where, Glen’s chart, we were?

all paleotemps and homo sapiens

Can we make the conclusion that ever since H. sapiens existed, the temperature did not really fluctuate? We probably could. From the chart above it is hard to see the rate of change since last 100 years, so here is a different chart from NASA (if you believe in NASA, which I do).

NASA GISS data

I believe that when we discuss with scientists, we might not be arguing whether the temperature is going up or down over a period of time, but we would argue how fast it is happening.