How Do We Know That CO2 Is Warming The Planet

canada goose IntroductionHow do we know canada goose black friday sale that we really need to act on climate change? canada goose

canadian goose jacket That’s the big question for human society today. For climate ‘alarmists’, if we fail to act, we will suffer serious and perhaps catastrophic losses in blood and treasure. For ‘denialists’, if we act, we will waste vast sums of money to solve a non existent problem and that will cause significant losses in blood and treasure. canadian goose jacket

Canada Goose Outlet I’d suggest that we can look at the sources of the buy canada goose jacket cheap knowledge that we do have. That will put us in a cheap Canada Goose better position to know what information is, or is not, trustworthy. Canada Goose Outlet

The big canada goose store question above breaks down into three large sub questions:

1) How do we know that CO2 (and other greenhouse gases) cause planetary warming?

2) How do we know that we are responsible for the measured increase in greenhouse gas concentrations?

canada goose uk shop 3) How do we know that warming will be a bad thing if it continues? canada goose uk shop

Let’s take them in turn, one or two Hubs per question. In this Hub we’ll ask:

canada goose clearance sale How Canada Goose sale do we know that CO2 (and other greenhouse gases) cause planetary warming? canada goose clearance sale

So how do we know CO2 warms the planet?Most people are surprised to learn that this part of the story goes back deep into the 19th century. Mathematician (and Napoleonic official) Canada Goose online Joseph Fourier had developed mathematical tools enabling him to accurately model the conduction of heat, and decided to use this ability to study the Earth’s temperature. What factors determined that temperature?

Canada Goose Parka Fourier considered all sources of heat to the surface: heat from the Earth’s interior, heat from solar radiation, heat from space itself, Canada Goose Jackets and did his best to calculate how these interacted. At the end of the process, he was left with a mystery: the planet should be considerably colder than it is. He realized that something about the Canada Goose Parka atmosphere altered the planet’s heat budget as he was able to calculate it. That ‘x factor’ would later be dubbed, somewhat misleadingly, the ‘greenhouse effect.’ As Fourier wrote in canada goose deals 1824: Canada Goose Parka

uk canada goose The heat of the sun, coming in the form of light, possesses the property of penetrating transparent solids or liquids, and loses this property canadian goose jacket entirely, when by communication with terrestrial bodies, it is turned into heat radiating without light. uk canada goose

Much information about energy flows in the atmosphere was gained over subsequent decades. But the essential question what exactly was physically responsible for this mysterious effect? remained unanswered until 1859.

In that year, an Anglo Irish physicist named John Tyndall constructed an ingenious apparatus for studying the transmission of heat through various gases. He found, much to his surprise, Canada Goose Outlet that a number of them had just the sort of property that Fourier had inferred: though transparent to light, they were in varying degrees opaque to radiant heat. Prominent among them were water vapor and carbon dioxide.

canada goose uk black friday Tyndall grasped the significance of this at once. If sunlight reached the ground and heated it (as we all experience fairly directly), but the heat could not so directly canada goose clearance sale escape again to space, then those gases would act much as a dam acts in a river: canada goose uk black friday

Canada Goose Online As a dam built across a river causes a local deepening of the stream, so our atmosphere, thrown as a barrier across the terrestrial rays, produces a canada goose clearance local heightening of the temperature at the Earth’s surface. Canada Goose Online

uk canada goose outlet The modern scientific basis developed from there. To mention just a couple of highlights, the first mathematical model of CO2 driven global warming was calculated by hand! in 1896 by Swedish Nobel Laureate Svante Arrhenius. The result caused considerable interest, but research subsided into confusion and uncertainty after a few years. uk canada goose outlet

cheap canada goose uk In 1938, Englishman Guy Callendar updated and extended Arrhenius’s work. Among other things, he: cheap canada goose uk

canada goose clearance Developed time series of temperature readings to demonstrate that global temperature was indeed increasing; canada goose clearance

Demonstrated that both atmospheric CO2 concentrations and temperature had increased since the 19th century; and

Updated the physical theory by incorporating the then new measurements of so called ‘back radiation’ from the atmosphere to the ground.

canada goose black friday sale Callendar did much to inspire canada goose coats and inform the next generation of researchers, such as the Canadian born Gilbert Plass, who developed computer software that enabled the detailed calculation of radiative transfers in the atmosphere. His work would eventually inspire comprehensive models of the Earth’s climate systems atmospheric composition and circulation, ocean temperatures and circulation, and carbon cycles among land, sea, and atmosphere, and more. canada goose black friday sale

canada goose coats A seminal figure in this work was Syukuro Manabe, a Japanese researcher who has spent most of his career in working in the United States. canada goose coats

canada goose uk outlet In 1967, he and Richard Wetherald had used a simple one dimensional model to calculate that a doubling of CO2 concentrations would raise global temperatures by around 2 degrees Celsius. (Then, as now, that was projected to be likely by the end of the 21st century.) canada goose uk outlet

cheap Canada Goose By 1975, the two had worked up a much more realistic three dimensional model. That one showed a rise of canada goose outlet 3.5 degrees. cheap Canada Goose

Canada Goose online By 1979, the National Academy of Science “Charney panel”, tasked to examine what climate models had to say about the possibility buy canada goose jacket of climate change driven by CO2, concluded that the panel was “unable to find any overlooked or underestimated physical effects” that could reduce expected warming below their range of 1.5 to 4.5 degrees C. Canada Goose online

Canada Goose Coats On Sale This estimate has held up very well; it currently represents the ‘likely’ range of sensitivity, according to the latest report of the International Panel on Climate Change. So we not only know that CO2 (and other greenhouse gases) cause warming, we have decent estimates of just how much they cause. Canada Goose Coats On Sale

buy canada goose jacket cheap But what about observations?What do we see happening with global warming and carbon dioxide in the real world? buy canada goose jacket cheap

Canada Goose Jackets Taking the latter first, atmospheric canada goose coats on sale carbon dioxide has increased roughly 40% since pre Industrial times. Before humanity embarked upon its current fossil fuel binge, canada goose the atmosphere held about 280 parts per million. Now that figure stands at about 400 parts per million. (As of writing, the latest available monthly estimate is for January, 2015, and that figure stands at 399.85 ppm. The most recent daily value you can see below.) Canada Goose Jackets.

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