copenlu/druid huggingface dataset:
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2022-02-08): Water vapor is Earth’s most abundant greenhouse gas. It’s responsible for about half of Earth’s greenhouse effect — the process that occurs when gases in Earth’s atmosphere trap the Sun’s heat. Greenhouse gases keep our planet livable. Without them, Earth’s surface temperature would be about 59 degrees Fahrenheit (33 degrees Celsius) colder. Water vapor is also a key part of Earth’s water cycle: the path that all water follows as it moves around Earth’s atmosphere, land, and ocean as liquid water, solid ice, and gaseous water vapor. [...] Some people mistakenly believe water vapor is the main driver of Earth’s current warming. But increased water vapor doesn’t cause global warming. Instead, it’s a consequence of it. Increased water vapor in the atmosphere amplifies the warming caused by other greenhouse gases. [...] But water vapor is a different animal. It’s condensable – it can be changed from a gas into a liquid. Its concentration depends on the temperature of the atmosphere. This makes water vapor the only greenhouse gas whose concentration increases because the atmosphere is warming, and causes it to warm even more.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2024-04-11): Additional compounds in the atmosphere including solid and liquid aerosol and other greenhouse gases, such as water vapor and ground-level ozone can also impact the climate. Learn more about these compounds and climate change on our Basics of Climate Change page. [...] Unlike many other greenhouse gases, fluorinated gases have no significant natural sources and come almost entirely from human-related activities. They are emitted through their use as substitutes for ozone-depleting substances (e.g., as refrigerants) and through a variety of industrial processes such as aluminum and semiconductor manufacturing. Many fluorinated gases have very high global warming potentials (GWPs) relative to other greenhouse gases, so small atmospheric concentrations can nevertheless have large effects on global temperatures. They can also have long atmospheric lifetimes—in some cases, lasting thousands of years. Like other long-lived greenhouse gases, most fluorinated gases are well-mixed in the atmosphere, spreading around the world after they are emitted. Many fluorinated gases are removed from the atmosphere only when they are destroyed by sunlight in the upper atmosphere. In general, fluorinated gases are the most potent and longest lasting type of greenhouse gases emitted by human activities.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2011-06-16): Because scientists know which wavelengths of energy each greenhouse gas absorbs, and the concentration of the gases in the atmosphere, they can calculate how much each gas contributes to warming the planet. Carbon dioxide causes about 20 percent of Earth’s greenhouse effect; water vapor accounts for about 50 percent; and clouds account for 25 percent. The rest is caused by small particles (aerosols) and minor greenhouse gases like methane. Water vapor concentrations in the air are controlled by Earth’s temperature. Warmer temperatures evaporate more water from the oceans, expand air masses, and lead to higher humidity. Cooling causes water vapor to condense and fall out as rain, sleet, or snow. Carbon dioxide, on the other hand, remains a gas at a wider range of atmospheric temperatures than water. Carbon dioxide molecules provide the initial greenhouse heating needed to maintain water vapor concentrations. When carbon dioxide concentrations drop, Earth cools, some water vapor falls out of the atmosphere, and the greenhouse warming caused by water vapor drops. Likewise, when carbon dioxide concentrations rise, air temperatures go up, and more water vapor evaporates into the atmosphere—which then amplifies greenhouse heating.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2024-03-18): Carbon dioxide, water vapor, and several other important greenhouse gases contribute to global warming via the so-called greenhouse effect. [...] Let's consider the principal GHGs one at a time, starting with water vapor, the most abundant greenhouse gas in the atmosphere according to NOAA's Climate.gov. To skip to a specific section, click on its link below. [...] On the one hand, because water vapor is a greenhouse gas, more water vapor could amplify the greenhouse effect and lead to further warming. On the other hand, increasing the humidity may result in more widespread cloudiness, thus reflecting more sunlight and cooling the Earth’s surface. Understanding and quantifying these competing effects is critically important to projecting future climate change.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2005-10-01): Water vapor is the most important GHG, since globally it is the most abundant of these gases, although it varies from 0-3% in a given location. NOAA's Carbon Cycle Greenhouse Gases (CCGG) group is concerned with the abundances of many of the other GHGs, since humans have a dominant role in the growing atmospheric concentrations of these gases. The gases measured by the CCGG include carbon dioxide (the second most important GHG), methane, nitrous oxide, sulfur hexafluoride, ozone, and a few others. While these gases constitute only a tiny fraction of Earth's very large atmosphere, their amounts are sufficient to absorb a major fraction of the infrared light in the atmosphere.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2022-08-17): Forcings: The initial drivers of climate. [...] - Greenhouse gas emissions. Since the Industrial Revolution, concentrations of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) have risen in the atmosphere. Burning fossil fuels such as coal, oil, and gas has increased the concentration of atmospheric carbon dioxide (CO2) from 280 parts per million to 416 parts per million.2 These greenhouse gases absorb and then re-radiate heat in Earth’s atmosphere, which causes increased surface warming. [...] The most abundant greenhouse gas, it acts as a feedback to amplify climate warming forcings. Water vapor increases as Earth's atmosphere warms, making it an important feedback mechanism to the greenhouse effect.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2019-05-13): Carbon dioxide (CO2): Carbon dioxide is the primary greenhouse gas, responsible for about three-quarters of emissions. It can linger in the atmosphere for thousands of years. In 2018, carbon dioxide levels reached 411 parts per million at Hawaii's Mauna Loa Atmospheric Baseline Observatory, the highest monthly average ever recorded. Carbon dioxide emissions mainly come from burning organic materials: coal, oil, gas, wood, and solid waste. [...] Other greenhouse gases include water vapor and ozone (O3). Water vapor is actually the world's most abundant greenhouse gas, but it is not tracked the same way as other greenhouse gases because it is not directly emitted by human activity and its effects are not well understood. Similarly, ground-level or tropospheric ozone (not to be confused with the protective stratospheric ozone layer higher up) is not emitted directly but emerges from complex reactions among pollutants in the air. [...] Greenhouse gases have far-ranging environmental and health effects. They cause climate change by trapping heat, and they also contribute to respiratory disease from smog and air pollution. Extreme weather, food supply disruptions, and increased wildfires are other effects of climate change caused by greenhouse gases. The typical weather patterns we've grown to expect will change; some species will disappear; others will migrate or grow. (Read more about greenhouse gas effects via climate change here.)
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2016-07-13): Recent climate changes, however, cannot be explained by natural causes alone. Research indicates that natural causes do not explain most observed warming, especially warming since the mid-20th century. Rather, it is extremely likely that human activities have been the dominant cause of that warming.[2] [...] When sunlight reaches Earth’s surface, it can either be reflected back into space or absorbed by Earth. Once absorbed, the planet releases some of the energy back into the atmosphere as heat (also called infrared radiation). Greenhouse gases like water vapor (H2O), carbon dioxide (CO2), and methane (CH4) absorb energy, slowing or preventing the loss of heat to space. In this way, GHGs act like a blanket, making Earth warmer than it would otherwise be. This process is commonly known as the "greenhouse effect." [...] Other greenhouse gases - Water vapor is the most abundant greenhouse gas and also the most important in terms of its contribution to the natural greenhouse effect, despite having a short atmospheric lifetime. Some human activities can influence local water vapor levels. However, on a global scale, the concentration of water vapor is controlled by temperature, which influences overall rates of evaporation and precipitation.[2] Therefore, the global concentration of water vapor is not substantially affected by direct human emissions.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2024-01-01): But human activities are changing earth's natural greenhouse effect with a dramatic increase in the release of greenhouse gases. Scientists agree greenhouse gases are the cause of global warming and climate change. [...] CO2 is released through natural processes, such as volcanic eruptions, plant respiration and animals and humans breathing. But the atmospheric CO2 concentration has increased by 50% since the Industrial Revolution began in the 1800s, due to human activities like the burning of fossil fuels and large-scale deforestation. Due to its abundance, CO2 is the main contributor to climate change. [...] It increases as the earth's atmosphere warms but unlike CO2, which can remain in the earth’s atmosphere for centuries, water vapour persists for only a few days.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2024-08-27): Greenhouse gases include carbon dioxide, methane, nitrous oxide, water vapor, tropospheric ozone and F-gases, which include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Carbon Dioxide (CO2) is the primary greenhouse gas contributing to recent climate change. It is absorbed and emitted naturally as part of the carbon cycle. However, human activities, such as the burning of fossil fuels and changes in land use, release significant additional amounts of CO2 into the atmosphere. [...] Water Vapor is the most abundant greenhouse gas and also the most important in terms of its contribution to the natural greenhouse effect, despite having a short atmospheric lifetime. Some human activities can influence local water vapor levels. However, on a global scale, the concentration of water vapor is controlled by temperature, which influences overall rates of evaporation and precipitation.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2020-10-16): The answer is that water vapor is indeed responsible for a major portion of Earth’s warming over the past century and for projected future warming. However, water vapor is not the cause of this warming. This is a critical, if subtle, distinction between the role of greenhouse gases as either forcings or feedbacks. In this case, anthropogenic emissions of CO2, methane, and other gases are warming the Earth. This rising average temperature increases evaporation rates and atmospheric water vapor concentrations. Those, in turn, result in additional warming. [...] Water vapor is a greenhouse gas, and sustained additional water vapor concentrations (resulting from higher average temperatures) will trap additional heat and result in additional warming. Increasing temperatures also influence cloud formation, though the relationship is complex and humidity is but one of many contributing factors. Clouds both trap heat below them, heating the Earth, and increase the reflectivity of the Earth (the albedo) by reflecting light off their white surfaces, cooling the Earth. There remains considerable uncertainty regarding the magnitude of cloud feedbacks, though many researchers believe that the net radiative forcing is either neutral or slightly positive. [...] Claims that water vapor is the "dominant" driver of recently observed climate change are spurious at best. While uncertainties in the magnitude of water vapor feedbacks are one of the key areas concerning climate change, none of this research casts any doubt on the role of carbon dioxide and other anthropogenic greenhouse gases as the initial forcings behind our current climate perturbation.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2022-06-15): - Five key greenhouse gases are carbon dioxide, nitrous oxide, methane, chlorofluorocarbons, and water vapor. [...] Water vapor is the most abundant greenhouse gas, but because the warming ocean increases the amount of it in our atmosphere, it is not a direct cause of climate change. Credit: John Fowler on UnsplashFEEDBACKS: A process where something is either amplified or reduced as time goes on, such as water vapor increasing as Earth warms leading to even more warming.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2024-06-27): This indicator describes how the levels of major greenhouse gases in the atmosphere have changed over time. [...] Ozone is also a greenhouse gas, but it differs from other greenhouse gases in several ways. The effects of ozone depend on its altitude, or where the gas is located vertically in the atmosphere. Most ozone naturally exists in the layer of the atmosphere called the stratosphere, which ranges from approximately 6 to 30 miles above the Earth’s surface. Ozone in the stratosphere has a slight net warming effect on the planet, but it is good for life on Earth because it absorbs harmful ultraviolet radiation from the sun, preventing it from reaching the Earth’s surface. In the troposphere—the layer of the atmosphere near ground level—ozone is an air pollutant that is harmful to breathe, a main ingredient of urban smog, and an important greenhouse gas that contributes to climate change (see the Climate Forcing indicator). Unlike the other major greenhouse gases, tropospheric ozone only lasts for days to weeks, so levels often vary by location and by season. [...] Loulergue, L., Schilt, A., Spahni, R., Masson-Delmotte, V., Blunier, T., Lemieux, B., Barnola, J.-M., Raynaud, D., Stocker, T. F., & Chappellaz, J. (2008). Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years. Nature, 453(7193), 383–386. https://doi.org/10.1038/nature06950
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2023-11-03): We can thank water vapor for about half of the "greenhouse effect" keeping heat from the sun inside our atmosphere.1 "It’s the most important greenhouse gas in our climate system, because of its relatively high concentrations," says Kerry Emanuel, professor emeritus of atmospheric science at MIT. "It can vary from almost nothing to as much as 3% of a volume of air." [...] And of course, temperatures today are rising, thanks to humans’ emissions of longer-lasting greenhouse gases like CO2. Water vapor amplifies that effect. "If the temperature rises, the amount of water vapor rises with it," says Emanuel. "But since water vapor is itself a greenhouse gas, rising water vapor causes yet higher temperatures. We refer to this process as a positive feedback, and it is thought to be the most important positive feedback in the climate system." In short, it’s true that water vapor is in some sense the "biggest" greenhouse gas involved in climate change, but it’s not in the driver’s seat. CO2 is still the main culprit of the global warming we’re experiencing today. Water vapor is just one of the features of our climate that our CO2 emissions are pushing out of balance—well beyond the stable levels humanity has enjoyed for thousands of years.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2024-03-25): Earth’s greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor. In addition to these natural compounds, synthetic fluorinated gases also function as greenhouse gases. Different greenhouse gases have different chemical properties and are removed from the atmosphere, over time, by various processes. Carbon dioxide, for example, is absorbed by "carbon sinks" such as forests, soil, and the ocean. Fluorinated gases are only destroyed by sunlight in the far upper atmosphere. [...] The most significant gases that cause global warming via the greenhouse effect are the following: [...] The most abundant greenhouse gas overall, water vapor differs from other greenhouse gases in that changes in its atmospheric concentrations are linked not to human activities directly, but rather to the warming that results from the other greenhouse gases we emit. Warmer air holds more water. And since water vapor is a greenhouse gas, more water absorbs more heat, inducing even greater warming and perpetuating a positive feedback loop. (It’s worth noting, however, that the net impact of this feedback loop is still uncertain, as increased water vapor also increases cloud cover that reflects the sun’s energy away from the earth but holds heat in at night.)
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2024-10-08): There are other greenhouse gases that are not counted in United States or international greenhouse gas inventories: Greenhouse gases are transparent to incoming (short-wave) radiation from the sun but block infrared (long-wave) radiation from leaving the earth's atmosphere. This greenhouse effect traps radiation from the sun and warms the planet's surface. As concentrations of these gases increase, more warming occurs than would happen naturally. [...] Last updated: May 2, 2024.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2016-04-27): Water vapour is the most abundant greenhouse gas in the atmosphere, yet other greenhouse gases (such as carbon dioxide and methane) are often portrayed as the main drivers of climate change. Why is that? Water vapour is the most abundant greenhouse gas in the atmosphere, both by weight and by volume (1), (2). Water vapour is also an effective greenhouse gas, as it does absorb longwave radiation and radiates it back to the surface, thus contributing to warming. When compared to other greenhouse gases, water vapour stays in the atmosphere for a much shorter period of time. Water vapour will generally stay in the atmosphere for days (before precipitating out) while other greenhouse gases, such as carbon dioxide or methane, will stay in the atmosphere for a much longer period of time (ranging from years to centuries) thus contributing to warming for an extended period of time.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2009-06-06): What about water vapor? Water vapor is the most abundant heat-trapping gas, but rarely discussed when considering human-induced climate change. The principal reason is that water vapor has a short cycle in the atmosphere (10 days on average) before it is incorporated into weather events and falls to Earth, so it cannot build up in the atmosphere in the same way as carbon dioxide does. However, a vicious cycle exists with water vapor, in which as more CO2 is emitted into the atmosphere and the Earth’s temperature rises, more water evaporates into the Earth’s atmosphere, which increases the temperature of the planet. The higher temperature atmosphere can then hold more water vapor than before. [...] Long-wave radiation absorbed by these gases in turn is re-emitted in all directions, including back toward Earth, and some of this re-emitted energy is absorbed again by these gases and re-emitted in all directions.
Claim: Water vapor is the most abundant greenhouse gas so it is the main cause of recent global warming (Facebook users, 2023-08-12)
Evidence (2023-12-08): Water vapor may be the most abundant GHG keeping the planet habitable, but it is not a major driver of long-term climate change and the recent global warming we are experiencing. It is incorrect to claim that because water vapor is natural and the greenhouse effect is natural, recent global warming must be natural. Water vapor is fundamentally different from the other GHGs which directly cause global warming. It has a negligible ERF, it leaves the atmosphere in a matter of days, and it is ultimately governed by temperature rather than human emissions. It is more of a consequence of global warming than a cause. We already know beyond any reasonable doubt that anthropogenic emissions of the other GHGs like CO2, methane, and nitrous oxide, is the primary cause of global warming. Water vapor is not relevant when it comes to the enhanced greenhouse effect in the context of recent global warming.
Claim: The consensus among scientists and policy-makers is that we’ll pass this point of no return if the global mean temperature rises by more than two degrees Celsius (Jonathan Franzen, 2019-09-17)
Evidence (2019-09-17): This statement makes a claim about the climate system that does not reflect our best understanding of how it works. The impacts and risks of climate change increase as warming continues, and limiting warming to the 2°C milestone has been chosen as an international goal, but it is not true that scientists expect runaway warming to begin if this milestone is crossed.
Claim: The consensus among scientists and policy-makers is that we’ll pass this point of no return if the global mean temperature rises by more than two degrees Celsius (Jonathan Franzen, 2019-09-17)
Evidence (2024-02-20): To prove this point, Kahan tested Republicans and Democrats on their scientific knowledge of global warming. He found that an overwhelming majority of both Republicans and Democrats know scientists believe CO2 causes global temperatures to rise. They also know that scientists believe that human-caused global warming leads to coastal flooding, rising temperatures and other ill effects. [...] Even assuming the consensus message does work, it will not necessarily lead to climate action by policymakers, said Mike Hulme, professor of climate and culture at King's College London. "Even if one takes the Cook et al. study at face value then how does a scientific consensus of 97.1 percent make policy-making about climate change any easier?" he wrote in an upcoming book on the consensus that he shared with ClimateWire.