Sometimes it makes sense to step back and look at the big picture. At a Wednesday Nite at the Lab lecture on the UW-Madison campus recently Todd LaMarskin of the Wisconsin Geological and Natural Survey detailed how paleoclimatology studies earth’s climate before we started keeping measurements with instruments. That means everything before about 150 years ago.
LaMaskin began by noting that most geologists are employed by the oil, gas and mining industries, and have a different perspective than academic geologists.
For example, the consensus of academic geologists is that things are happening to the temperature, sea level, distribution and length of the seasons that are not natural, and are best explained by the atmospheric abundance of greenhouse gases – while the American Association of Petroleum Geologists on April 6 came out with a statement supporting recent Congressional action to block the EPA from regulating greenhouse gasses. Humm.
We may think waiting for a red light to change takes a long time. Geologists look at time a little differently. LaMaskin compared geologic time to a 24 hour clock.
The first 21 hours of life on earth are very difficult for us to know much about. The final 3 hours is when multicellular life forms developed and when things start to get interesting to us mammals.
The single largest extinction event, in which 96% of all marine life disappeared form the planet, occurred a mere 76 minutes ago on the geologic clock (or 250 million years ago).
The famous extinction event that killed the dinosaurs was occurred with 20 minutes left to the present or only 65 million years ago.
We have an excellent fossil record during the mammal dominant period. We can learn from the l fossil record how animals have responded to climate change in the past. We know these temperature swings cause dramatic variations in the biota in the earth. Major migrations of species. Major changes in forest and amount of forest fires. What we don’t have is any record of what happened to human civilization because there was no human culture.
Our oldest ice records only go back 14 seconds. The Industrial Revolution (which started our current deadly spiral) occurred just .004 seconds ago.
Scientists use many methods to study ancient climate including the rate that minerals decay, and they have synchronized rock clocks around the world to understand earth history. They also use precipitated calcium in cave deposits, tree rings and sediment cores from the ocean floor.
Zoom in on last 20,000 years and see that in general we have experienced a long-term warming. 13,000 years ago there was a big increase in snow accumulation. The leading theory about why this cool period was disruption of Thermohaline Circulation. Warm water from equator makes its way to northern Atlantic to heat and moderate the climate of Europe. If the Thermohaline Circulation is cut off in the north, warm water will not make it’s way to Europe, plunging it back into a very cold state. We think that happened before because of a disruption of the Thermohaline because of a sudden influx of fresh water during deglaciation of North America. Some people see that occurring again now.
As glaciers melted from 18000 years ago, we have seen sea level rise by hundreds of meters. It was about 120 meters lower during glaciation.
The sea level then became steady. Now it’s rising again over the past 150 years.
And as for temperature and CO2 levels, if we look back to the year 1000, 2000 and today, the graph looks like a hockey stick with a large and abrupt increase in temperature.
We are creating a climate for ourselves that humans have never experienced before.
Here is a quote from Climate Progress.com about what is going on in Oklahoma at the moment:
- Today marks the 29th consecutive day over 90. That is a record.
- Today is forecast to be the 10th day above 100 in June. That is a record.
- Today marks the 34th consecutive day above normal.
- June 2011 set or tied single-day record high temperatures on the 17th, 18th, 19th, and 27th. Those record temperatures were 103, 104, 101, and 103 degrees, respectively.
These statistics beat those of the dust bowl. Texas is hoping for a hurricane that might bring rain to their parched earth. Arizona and New Mexico have both had their biggest forest fires ever this summer.
Categories: Climate Change