Global Warming at 4 Hiroshima Atomic Bombs Per Second

Our climate is absorbing a lot of heat. When scientists add up all of the heat warming the oceans, land, and atmosphere and melting the ice, they find our climate is accumulating 4 Hiroshima atomic bombs worth of heat every second. This warming is due to more heat-trapping greenhouse gases in the atmosphere. The burning of fossil fuels means we are emitting billions of tonnes of carbon dioxide every year. This is the main contributor to global warming. To communicate the sheer amount of heat our planet is accumulating, we have created this widget, embeddable on blogs and also available as a Facebook app, an iPad app, and an iPhone app. To help get the word out on just how much global warming our planet is experiencing, add the widget to your own blog or use the widget on Facebook, like it and share it. To get the iPhone or iPad app, visit this site on your device and use the big “Get...” button to get instructions. The app is not available through the Apple App Store. Accumulating Heat The earth has warmed rapidly over the past century due mainly to human activity, and especially over the past few decades. The increased greenhouse effect has warmed the land and air and melted ice, but most of it (about 90%) has gone into heating the oceans. Several Skeptical Science contributors worked together to publish a scientific paper1 which combined the land, air, ice, and ocean warming data. It found that for recent decades the earth has been heating at a rate of 250 trillion Joules per second. “Joules per second” is a difficult unit of measure to appreciate, and is especially foreign to people who are unfamiliar with science. This widget attempts to put that heating into terms that are easier to visualize. 250 trillion Joules per second is equivalent to: Learn More About... Climate Heat Carbon Dioxide Impacts The Climate and Heat The earth's climate system absorbs heat in many different ways. Increases in the temperatures that people experience day to day are only one of several reservoirs for accumulating heat. While changes in the atmosphere are the easiest to recognize, they are also the most variable and subject to “noise”. Changes in the ocean, where most of the heat is going, have been more steady, while the melting of vast stores of ice is accelerating. The earth continues to warm, day after day, at a concerning rate. Learn More About Heat in the... Ocean Atmosphere Land Melting Ice Trends Climate Trends When the energy from all of the earth's “heat” reservoirs is combined, the clear, decades long trend is unequivocal and staggering. With the exception of short “hiatus” periods, the earth has been gaining heat, virtually continuously, at an average rate of 250 trillion Joules per second, and this trend shows no serious sign of ending. Greenhouse Gases Without greenhouse gases, the temperature at the surface of the earth would be a mere -15°C (5°F). Life on earth is made possible by greenhouse gases. The earth's atmosphere is mostly transparent to incoming sunlight, which passes through and warms the surface of the earth. Warm objects in turn emit another wavelength of light, one invisible to the human eye, termed “infrared radiation”. Like visible light, infrared radiation passes through the atmosphere and into space. But small traces of greenhouse gases, such as carbon dioxide, are not transparent to infrared radiation. They absorb and re-emit that energy, trapping some of that heat within the atmosphere. Climate Changes Changes in the climate are visible all around us. Some are subtle and seemingly inconsequential, but these changes are accelerating and undeniable. Spring comes earlier. Tree lines and species are migrating poleward and upward. Glaciers and Arctic ice are retreating at an alarming rate4. Sea levels are rising5. Every day, more and more studies point towards a changing and warming world in new and sometimes unexpected ways. Climate Change Fingerprints The indicators that recent climate change is the result of burning fossil fuels, rather than from some unknown natural variation, are clear and consistent with what we do know. There are subtle differences to how the world will warm due to greenhouse gases compared with other potential sources (such as an increase in the warmth of the sun). Most importantly, scientists know that greenhouse gases would cause the upper atmosphere to cool rather than warm. We also know that the source of the additional carbon dioxide in the atmosphere is due to burning fossil fuels. The carbon in fossil fuels differs from atmospheric carbon because it has less of the isotope known as 13C (Carbon-13), a heavier-than-normal version of carbon. Plants generally prefer the lighter and more common 12C (Carbon-12) for photosynthesis, so fossil fuels, which are produced from decayed plant matter, are deficient in 13C. As a result, when we burn fossil fuels we cause the percentage of 13C in the atmosphere to drop, and this change has been detected. 450 ppm Scientists have established that climate change greater than 2°C (4°F) will likely be extremely dangerous. We are likely to have committed our planet to that degree of warming when atmospheric carbon dioxide concentrations reach 450 ppm (parts per million). The natural, pre-industrial level of carbon dioxide (CO2) was around 285 ppm. The level of CO2 is currently near 400 ppm. That level of carbon dioxide, 400 ppm, has not been seen in the atmosphere for millions of years. At the current rate, adding 2 ppm per year, we will reach 450 ppm around the year 2038, a mere 25 years from now. Impacts of Climate Change Not all effects of climate change can be anticipated, and not all effects that are anticipated may come to pass, but the number of expected, negative impacts on human society present a clear and worrying danger.28 Some of these impacts are already being felt, to varying degrees, although many will not seriously present themselves until temperatures increase by 2°C or more (although we have already committed to more than 1.4°C of warming, depending on actual climate sensitivity). Ecosystem changes, species range shifts and extinctions Threats to food supplies Threats to water supplies Increased and more frequent damage from storms, fires and floods Changes and increases in disease vectors Increased morbidity and mortality from heat waves, floods and droughts It is important to realize that no matter how strong these impacts are felt now, they will grow worse over time, and when they do, we will have no ability to reverse any of them. Ocean Heat More than 90% of all heat being absorbed by the earth, each and every day, is going into the oceans. The ocean, when viewed from a climate perspective, is often considered in three layers: The surface to 700 meters down. 700 meters to 2000 meters down. 2000 meters down to the bottom (average is about 3800 meters). For some time, scientists believed that ocean warming would be restricted to the upper 700 meters and that global warming would take a very long time to penetrate deeper than that. Recent studies2 and modern measurement techniques have shown, however, that the ocean below 700 meters is heating as well, and the amount of energy that it takes to do so is staggerring. Learn More About... The Ocean: How We Know Scientists2 use ocean heat content measurements from ARGO floats, as well as data from expendable bathythermographs (XBT) and mechanical bathythermographs (MBT). Argo is an international project to collect information on the temperature and salinity of the upper part of the world's oceans. Argo uses robotic floats that spend most of their life drifting below the ocean surface, reaching depths of 2000m and spending periods of approximately 10 days below the surface. Floats take temperature and salinity measurements as they rise to the surface. After surfacing they transmit their data to satellites and then submerge to repeat the data collection cycle. Currently, there are roughly 3000 floats producing 100,000 temperature/salinity profiles per year. A bathythermograph is an instrument which has a temperature sensor and is thrown overboard from ships to record pressure and temperature changes as it drops through the water. These were the main instruments used to measure OHC before the ARGO float network was deployed starting about a decade ago to provide more accurate and consistent data. The Ocean: What We Know The ocean accounts for more than 90% of the heat absorbed by the earth in the past 30 years. The total increase in heat content of the oceans over the period from 1955-2010 was 24 x 1022 (240,000,000,000,000,000,000,000) Joules. The energy absorbed by the oceans will not quickly dissipate. As the ocean warms it expands, leading to marked sea level rise. Increased ocean temperatures help to warm the atmosphere. Increased ocean temperatures help to generate and intensify storms. Warmer waters, combined with ocean acidification, are pushing some forms of marine life beyond their limits. The Atmosphere Changes in the temperature of the earth's atmosphere are the easiest to measure and the most obvious in an individual's personal experience, but the atmosphere is also the most variable. One very warm year can be followed by several cold ones, while one region may experience an unusual cold snap while many other parts of the globe endure record warmth. Many factors can influence global atmospheric temperatures over short time frames of a few years, which in turn disguises the insistent, uninterrupted warming which is occurring overall. Nevertheless, the atmosphere has warmed by 0.8°C (1.4°F) in the past century. This warming is more exaggerated at the poles, leading to even greater swings in temperatures further from the equator. Yet it still accounts for only 2% of total heat absorbed by the earth's climate. Variability Scientists and statisticians have worked together to try to quantify and eliminate the most obvious forms of variability in global atmospheric