Wood Romances

In my first two posts in this series , I described the bad behavior of cherry-picking short-term trends and choosing the wrong scale to hide the incline of global temperatures. Here I want to consider the trick of using local (or regional) temperatures in place of global temperatures. As best I can tell, there are at least two reasons why people might want to do this. Some people want to say that global warming is good, the world is starved of CO2, and we need to add more CO2 to the atmosphere. Unsurprisingly, two of the most prominent proponents of this tactic are former geologists for the fossil fuel industry. They want to show that societies thrive when global temperatures are warmer. Others using this tactic seem to want to say that global temperatures don't correlate with CO2. And what better way to make that point than to use local temperatures instead of global temperatures? Prepare for some snarkiness.  Using Local Temperatures to Say Global Warming Is Good Imagine you ha...

If you spend much time on social media discussing climate science, you're likely to come across a graph that looks like the above. The argument associated with this will be that this graph shows that climate has been variable throughout the Holocene and modern warming is neither unprecedented nor unusual compared to other warming periods at other times during the Holocene. However, it would appear this graph is completely fake. There are multiple versions of this graph floating around the internet, and they conflict with each other, and some of them, like the one above claiming to be Greenland ice core data, are complete nonsense. Let's look at two common versions of this graph. Greenland Ice Core Versions Greenland ice core versions of this graph can be found promoted widely on the internet. The particular version above is unsourced, but based on what it presents, it can easily be seen to be faked. First, it claims to be ice core data from the Crete site in central Greenland, ...

We are often conditioned to think climate changes that occur naturally are always slow and gradual. However, the geologic evidence we have shows that there major exceptions to this general rule. Perhaps the most widely-cited is the onset of the Younger Dryas - a well known abrupt climate change in which temperatures changed rapidly, perhaps by 10°C in a few decades, with completely natural causes. The episode is most easily identified in the GISP2 Greenland ice core record. According to the ice core record, cooling began about 14,500 years ago, followed by an abrupt cooling event about 13,000 years ago. That cooling period ended just as abruptly 11,500 year ago, and recovery from the last glaciation continued into the Holocene. Abrupt shifts in temperatures in agreement with these time frames were also seen in other places around the globe, including the Cariaco Basin in Venezuela and varved lake sediments in Europe. This raises a couple interesting questions: 1) what caused the abrupt...