From TheDenverChannel.com (Mike Nelson):
Temperatures soared to 98 degrees in Denver Monday afternoon – way above the average high of 82 degrees for mid-June, but shy of the record of 102 degrees, set on June 14, 2006.
Colorado is on the eastern edge of a huge bubble of hot, dry air that covers all of the southwestern United States. This hot, dry airmass has little thunderstorm potential, just a few hit or miss storms to bring brief relief from the heat…
Western Colorado, Utah, Nevada, Arizona, New Mexico and California are all experiencing extreme drought conditions. The drought exacerbates the heat wave as the sun’s heat is simply heating up ground as opposed to evaporating water. This compounds the cycle of heat and dryness and is not likely to break for most of the summer.
The hottest weather of the year is typically in mid-July, so this is an early heatwave. With global warming we are seeing hotter weather earlier, so this type of event will become more frequent…
If we reach 100 degrees Tuesday and Wednesday, it would be the earliest ever Denver has had two straight days of triple digits.
June 2012 had 6 days of 100 degrees or hotter, with 2 days reaching 105 degrees – the all-time hottest temperature for Denver. (It has been reached several different days in June, July and August.)
Our hottest weather is typically in July, but we are seeing heatwaves coming earlier in the warm season, while our mid-summer heatwaves are tending to become longer and hotter in recent decades.
The role of climate change cannot be left out of the equation in this weather pattern. As the level of carbon dioxide (CO2) increases in our atmosphere, our world is getting warmer. The effect of increased CO2 in our atmosphere is well understood and has been known for over 150 years…
The role of carbon dioxide (CO2) in determining the temperature of our planet is established science, regardless of efforts to discount the impact of CO2.
In 1825, a French mathematician — Joseph Fourier — calculated that given the distance from the Sun, the Earth should be much colder. He theorized that it was the atmosphere that trapped enough heat to make our planet habitable.
In 1856, Eunice Foote, an American researcher, filled glass jars with different gases and set them in the sun. The jar filled with CO2 warmed the most.
In 1863, John Tyndall, an Irish physicist, did more elaborate experiments with carbon dioxide and discovered that CO2 was very effective at trapping long-wave or Earth energy.
In 1895, a Swedish researcher named Svante Arrhenius theorized that a doubling of carbon dioxide in the atmosphere would cause the Earth’s average temperature to increase by several degrees. The greatest impact would be in the far northern latitudes – which is exactly what we are seeing!
In the 1970s – CBS anchorman Walter Cronkite, who was famously known as the most trusted man in America, reported on the threat of global warming.
Even though CO2 is a TRACE gas in our atmosphere, it is highly effective at capturing infrared (Earth) energy from escaping into space. The CO2 molecule vibrates a little when infrared energy passes by, this tiny “wiggle” serves to trap that energy in the atmosphere instead of letting it pass through into outer space…
On timescales of millions of years, CO2 is mostly a balance between volcanoes that create it and “chemical weathering” (dissolving) of rocks that destroy it. The weathering of rocks creates calcium carbonate that returns the carbon to the soil, the oceans and the Earth’s crust.
When volcanic emissions exceed rock dissolving, CO2 increases and vice versa when volcanic emissions decline.
CO2 was extremely high (maybe 5 times current levels!) 55 million years ago (more volcanoes than dissolving rocks), and it fell steadily for 50 million years straight.
The main reason that CO2 dropped was that India crashed into Asia, raising the Himalayas and Tibetan Plateau. All that fresh rock dissolved fast, sucking down CO2.
When the CO2 got low enough about 2 million years ago (about 300 ppm), we started having ice ages. We have had at least 20 since then.
During ice ages, about ⅓ of all the CO2 dissolves into the oceans, so CO2 drops to around 200 ppm. Then, when the ice melts, it shoots back up to about 300 ppm again. It’s done this 20 times in 2 million years.
During the last great global warming, CO2 rose from 180 to 280 ppm between 18,000 years ago and 8,000 years ago. That’s a rise of 0.01 ppm per century.
Now, as we dig up fossil carbon and light it on fire, the CO2 rises 3 ppm per year, 300 times as fast as it during deglaciation! It is not just the fact that the world is getting warmer, it really is the rate at which the warming is occurring. Since 1800, the CO2 has risen more than it did in 100 centuries after 16,000 BC.
With things changing so quickly, the big concern is how will we deal with the rapid change and whether many species will be able to survive, as there is not time for them to evolve…
Even though an individual severe weather event cannot be blamed on Global Warming, a warmer climate adds energy to the system — “juicing up” the atmosphere and will cause more frequent and extreme severe weather events in the future.
We can expect more intense rain events, such as the Front Range Flood in September 2013, but also more wildfires as the changing climate creates stress on our forests.
Our Colorado climate will become warmer over the next 100 years. Denver will have temperatures more like Albuquerque, New Mexico.
The result will be less snowpack, lower reservoirs and more frequent droughts. We know the population will increase and therefore the demand for water – we need to plan ahead! We have been blessed to have a few big snow years recently, the long-term prospects may not be so rosy.