What is Global warming: Definition and 222 Discussions

Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, humans have since the mid-20th century had an unprecedented impact on Earth's climate system and have caused change on a global scale.The largest driver of warming is the emission of gases that create a greenhouse effect, of which more than 90% are carbon dioxide (CO2) and methane. Fossil fuel burning (coal, oil, and natural gas) for energy consumption is the main source of these emissions, with additional contributions from agriculture, deforestation, and manufacturing. The human cause of climate change is not disputed by any scientific body of national or international standing. Temperature rise is accelerated or tempered by climate feedbacks, such as loss of sunlight-reflecting snow and ice cover, increased water vapour (a greenhouse gas itself), and changes to land and ocean carbon sinks.
Temperature rise on land is about twice the global average increase, leading to desert expansion and more common heat waves and wildfires. Temperature rise is also amplified in the Arctic, where it has contributed to melting permafrost, glacial retreat and sea ice loss. Warmer temperatures are increasing rates of evaporation, causing more intense storms and weather extremes. Impacts on ecosystems include the relocation or extinction of many species as their environment changes, most immediately in coral reefs, mountains, and the Arctic. Climate change threatens people with food insecurity, water scarcity, flooding, infectious diseases, extreme heat, economic losses, and displacement. These impacts have led the World Health Organization to call climate change the greatest threat to global health in the 21st century. Even if efforts to minimise future warming are successful, some effects will continue for centuries, including rising sea levels, rising ocean temperatures, and ocean acidification.

Many of these impacts are already felt at the current level of warming, which is about 1.2 °C (2.2 °F). The Intergovernmental Panel on Climate Change (IPCC) has issued a series of reports that project significant increases in these impacts as warming continues to 1.5 °C (2.7 °F) and beyond. Additional warming also increases the risk of triggering critical thresholds called tipping points. Responding to climate change involves mitigation and adaptation. Mitigation – limiting climate change – consists of reducing greenhouse gas emissions and removing them from the atmosphere; methods include the development and deployment of low-carbon energy sources such as wind and solar, a phase-out of coal, enhanced energy efficiency, reforestation, and forest preservation. Adaptation consists of adjusting to actual or expected climate, such as through improved coastline protection, better disaster management, assisted colonisation, and the development of more resistant crops. Adaptation alone cannot avert the risk of "severe, widespread and irreversible" impacts.Under the 2015 Paris Agreement, nations collectively agreed to keep warming "well under 2.0 °C (3.6 °F)" through mitigation efforts. However, with pledges made under the Agreement, global warming would still reach about 2.8 °C (5.0 °F) by the end of the century. Limiting warming to 1.5 °C (2.7 °F) would require halving emissions by 2030 and achieving near-zero emissions by 2050.

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  1. M

    Tidal friction and global warming

    Ignoring global warming, the Earth will spin progressively slower. But how will global warming affect this? THEY say, LESS water, LESS slowing. > slowing spin is all about the FRICTION from the action of WATER on the LAND, when the water is gone the slowing of the spin will ceased (or at least...
  2. J

    What happens to the IR radiation that the Greenhouse gases don't absorb?

    I have been searching for the answer yet – as I'm here – didn't find it. The current model of climate warming says the lower parts of Earth's atmosphere don't allow the IR radiation to escape freely to the outer space because the GH gas molecules keep absorbing it virtually as soon as it's been...
  3. hagopbul

    Climate Problems: Debating the Science Behind It

    Hello All : Reading about climate problems , and noticed that there is some deniers or people who do not convinced with the climate problem scientific ideas ( or theories ) may i ask what scientific claims they use to refute the current scientific explanation for the climate problems ? is...
  4. practicalphysicsnoob

    Chemical/Paint Best transparent material that allows infrared to pass through?

    Trying to create a version of mass producible radiative cooling panels At first I want to start off with something able to be created at home relatively cheaply as I dive further in I will start trying to find more durable materials with the same capabilities In order for the system to work the...
  5. jaketodd

    Adding to our knowledge on global warming, and a question

    https://journals.ametsoc.org/view/journals/bams/89/9/2008bams2370_1.xml?tab_body=pdf I want to add this to the literature base here on physics forums. I'm curious: Are there any reputable papers that say contrary to this one? Or, is it a complete myth the earth goes through heating and...
  6. pinball1970

    Record Heat for the Oceans in 2022

    "Changes in ocean heat content (OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving...
  7. S

    I Could a bubble shield at L1 combat global warming?

  8. moriah

    How Do Methane and Hydrogen Sulfide Contribute to Global Warming?

    Methane and hydrogen sulfide are supposed to be heavier then air, thus why they remain in low lying areas. I am to believe that only when they begin to disintegrate, they rise into the atmosphere. So my question is, if these gases are already disintegrated, how can they be so formidable?
  9. 256bits

    Project Drawdown - Plan to Reverse Global Warming

    Usually it is just about the nasty oil, and goodness of electricity. Of the 100 solutions Project Drawdown has listed, some would not even be considered along with the more commonly known by the public at large https://www.drawdown.org/ From cultivation of rice ( number one crop of the world )...
  10. BigDumDum

    Fluid Dynamics and Global Warming

    Almost 90% of all humanity lives in the Northern hemisphere. Due to colonization, expansion, growth, war, water sources, etc. we have amassed our populations in specific areas around the Northern hemisphere. We continue to build at an unprecedented rate. Our buildings are growing wider, taller...
  11. S

    Has a change in the cosmic rays hitting Earth been causing Global Warming?

    I found this link off of a politically charged website (of the persuasion to deny that Global Warming exists), so I am apt to be skeptical. (The website is hosted at the Northern Marianna Islands, making me even more suspicious.)...
  12. M

    Ending global warming with Maxwell's demon

    As a start for discussion I'd like to make the following bold claim: Both the problems of enough usable energy and global warming can be resolved by implementing Maxwell's demon on a large scale. To justify this bold statement somewhat, I'd like to point to a (relatively) recent...
  13. Auto-Didact

    News Scientists turn CO2 back into coal

    Climate rewind: Scientists turn carbon dioxide back into coal The article says that this process takes place using a liquid metal catalyst at room temperature and is both efficient and scalable. The rest of the article can be read over at phys.org (link in title). The published paper (open...
  14. S

    B Wouldn't fusion reactors also cause global warming?

    A fusion reactors releases a lots of energy. Most of this energy will end up as thermal energy after it has been used by the consumers. Wouldn't this heat up the earth? People use the energy to run cookers, drive cars, light up houses, etc. This energy (99%?) will end up as thermal energy where...
  15. SamRoss

    Where can I find historic daily average temperatures?

    I am a middle school teacher who is very concerned about global warming. My students’ memories don’t go back very far and they think it is perfectly normal to see mild weather and little to no snow throughout the winter months in New York City. I would like to compare current temperatures each...
  16. P

    Future of the Atmosphere W/Unregulated Pollution?

    In a future (100, 500, and 1000 years in the future specifically) where industrial and domestic pollution is totally unregulated, what does the composition of the atmosphere look like? And what do weather systems look like? I know this is an extremely broad question, I'm just looking for a few...
  17. kyphysics

    Does Global Warming Impact Locales Causing it More?

    We know that greenhouse gases are the biggest cause of global warming and that the Earth has gotten warmer and warmer over the past few decades. Question: Since not all locales produce greenhouse gases (namely, carbon dioxide) equally, are the effects of global warming distributed more to...
  18. A

    Agres, introduction & ice sheet modeling issue

    I always had an interest in science. At SUNYA, I took a lot of science, and did modeling for Jay Forrester's Club of Rome Report. My junior thesis was based on that work, and my advisors laughed at it, so I decided that I did not want a degree from SUNYA. My second choice university did not...
  19. Ophiolite

    New York Flood Risk through 2300 CE

    This recent Open Access article in PNAS reviews flood risks in NY through 2300 CE. The findings are summarised in the Significance paragraph: We combine downscaled tropical cyclones, storm-surge models, and probabilistic sea-level rise projections to assess flood hazard associated with changing...
  20. D

    An idea to reverse global warming

    Elon Musk says we can terraform Mars by converting its CO2 and H2O into CH4 and O2 using solar power, the latter two compounds being quite useful. Can't we use his idea to reduce the CO2 in our atmosphere and reverse global warming?
  21. Arman777

    I Sun's Magnetic Field, Global Warming

    In the class our prof said, Sun changes its magnetic poles in every 11 year.And when changes the black spots on the sun increases Is this true ? Also she said Sun's cosmic radiation waves destroyes the upper atmosphere of earth.It was something like this.I don't quite remember.Actually thata...
  22. TMT

    Can We Generate Perpetual Machine in 2nd Degree from Global Warming Heat?

    Concerning Global warming; Can we cool atmosphere by converting it's heat content to electricity? if we do so is it became a perpetual machine in 2nd degree or not? I'm not so good in thermodynamics. But I'm sure it will not violate 1. rule energy is not created from noting, energy converted...
  23. A

    What is causing the dramatic rise in Arctic temperatures?

    It seems Chip Knappenberger of the Cato Institute, who is considered something of a global warming skeptic, has made an interesting statement. “Natural variability is itself is becoming increasingly ‘non-natural’ as it includes influences which themselves are shaped by anthropogenic...
  24. resurgance2001

    Carbon dioxide and global warming

    Hi I have a simple question about global warming. The percentage of carbon dioxide in the Earth atmosphere is about 0.04% . My question is how is such a small percentage of this gas able to have such a powerful affect on global warming? Thanks
  25. H

    What is the impact of the sun on global warming?

    I would imagine that most here believe in global warming. My question is what effect does the sun have on global warming because the heat increases as it's fuel is consumed.
  26. W

    Global Warming - why half a degree matters

    1.5 C vs 2 C global warming: New study shows why half a degree matters Global warming is scary. It makes me wonder why people don't take it too seriously. Though I have read somewhere that the energy consumption of the US actually went down by a bit last year so maybe people are taking baby...
  27. dakota224

    Problem: using thermal expansion to calculate sea level rise

    Homework Statement Since the 1980's a total of 20 x 10^22 J of additional energy has been absorbed by the worlds oceans. This is 90% of the additional heat our planet is storing as a consequence of global warming. The surface area of the worlds oceans is 361,900,000 km^2 and we will assume this...
  28. Andy Resnick

    Is Global Warming Responsible for My Amazing Astrophotography?

    It's awesome because I am able to be outside imaging during January. No snow on the ground and not unreasonably cold. This is the first year I've been able to consistently image Orion- here's a full-frame and 100% crop of Orion Nebula, 21m total exposure, 800/5.6 ISO varied from 640-2000, 6s...
  29. T

    Is the 'Rising Sea Levels' Argument for Global Warming Valid?

    I'm so tiredd of hearing Obama and his global warming ilk use the 'seas will rise' because of melting polar ice argument. There are two kinds of ice on the planet, the ice that is free floating such as much of the northern pole area, and ice that is not floating such as Antarctica and glaciers...
  30. F

    Contribution of mobile phones to global warming

    Hi, Where can I find a research or statics about the contribution of cellulars or general mobile devices (tablets, PDAs) to the global warming? But I am looking for specifically cellular phones for a project. Thanks a lot!
  31. S

    Why does the heat in the atmosphere mostly go down?

    The wiki article on the greenhouse effect (https://en.wikipedia.org/wiki/Greenhouse_effect) has a top illustration which shows the flow of heat and energy (Watts per meter squared) between outer space, the atmosphere, and Earth's surface. The illustrations shows that of the 519 in the...
  32. TheMathNoob

    Positive feedbacks and negative feedbacks (global warming)

    Homework Statement Consider the feedback loop involving Clouds, Rainfall and forest area. All the relationships represented in this figure show positive couplings between the components: Forest area is positively coupled to rainfall, plant evapotranspiration is positively coupled to forest...
  33. W

    Other Physics professor denies climate change

    My first post here. I'm not sure who else to consult. Yesterday in my "Technical Physics" class, my professor went on a rant about climate change. He denied that the Earth is warming at all, but instead cooling due to solar activity. He made a claim that we are actually headed for a cooler...
  34. UMath1

    Landfill methane gas emissions

    I read that biodegradable waste in landfills produces methane, a harmful GHG. But didn't biodegradable waste always exist? We throw paper away, but the trees we produce paper from would have died eventually. Our organic waste comes from plants and animals that would have died eventually too. So...
  35. Khatti

    Carbon Extraction from the atmosphere

    I sort of wandered in from the Science Fiction Forum before anyone could stop me. I have a thought that I simply lack the expertise to make use of, and I thought I would drop it in the laps of people who do have the expertise to make use of it. What would be involved to pull carbon directly...
  36. Greg Bernhardt

    Climate Change threads are back

    After much deliberation we have unbanned climate change / global warming threads from the Earth forum. Before you go a start a thread, make sure you read the new rules https://www.physicsforums.com/showthread.php?t=757267
  37. Greg Bernhardt

    Climate Change / Global Warming Policy

    Before posting anything, please review the Physics Forums Global Guidelines. CC/GW threads in this forum are intended for discussion of the scientific content of well-researched models of weather, climatology, and global warming that have been published in peer-reviewed journals and...
  38. J

    Why was confirming Higgs mechanism worth it?

    I'm just looking for a layman's explanation of why the efforts to confirm Higgs was truly necessary and worth the expense. The counter-argument is that theoretical physics seem to be going along just fine assuming something like the Higgs mechanism existed without validating it. Also, nothing...
  39. Eagle9

    The question about volcanic ashes

    Good day :smile: It is well-known fact that the volcanic eruptions cause the global decrease of average temperature. I quickly reviewed the article in wikipedia and several questions arised regarding this issue. There is written in this article (I do not trust Wikipedia very much): 1) So, the...
  40. 1

    What is the Physics behind Global Warming?

    Hi all, I'm a 1st year physics student in the UK and I'd like to ask if anyone could point me to where I can learn about the in-depth science of global warming/climate change. I don't like having to appeal to authority (even when the authority is legitimate) during debates on global warming and...
  41. Greg Bernhardt

    Energy Department grants $226m to NuScale Power

    Energy Department to Give $226 Million to Support Nuclear Reactor Design http://www.nytimes.com/2013/12/13/business/energy-environment/energy-dept-to-give-226-million-to-new-nuclear-reactor-design.html?_r=1&
  42. C

    Methane and CO2 atmospheric lifetime math problem

    Homework Statement On a per-molecule basis, methane is 26 times more effective as an infrared absorber than is CO2. Calculate the corresponding ratio on a per-unit-mass basis, and compare it with the 20-year GWP for methane. What's the reason for any discrepncy you find? (CO2 atmospheric...
  43. anorlunda

    What is causing the annual variations in sea level in the Florida Keys?

    In southern Florida, and especially in the Florida Keys, there are some very shallow areas that make it very obvious how low low-tide is. I'm stumped to notice that there seems to be significant variations from year to year. For example, an area we call the flats is normalls under six...
  44. zoobyshoe

    The Deadly Asian Giant Hornet: A Growing Threat to Humans and Honeybees

    Go here to see the horrible picture: http://www.relevantmagazine.com/slices/asian-giant-hornets-worst-thing-world Apparently these are real. Wiki has an article about them, anyway.
  45. N

    What is your opinion on climate change? Man-made or not?

    There's been a lot in the news recently about climate change, global warming, and whether or not it is primarily caused by human activity. I know many studies have been done on the issue, but it seems for every study done saying it is man-made, another comes out saying it is not, and vice versa...
  46. B

    Standardizing Elephant Weight: A Global Scientific Challenge

    Recently, reading an article about graphene, it was disclosed that a sheet of graphene the thickness of a piece of plastic wrap could support the weight of an elephant balanced on a pencil. Beyond the fact that I highly doubt anyone got an elephant (although good at balancing tricks I have seen...
  47. T

    Heating of atmospere by Sunlight(Not Climate change or global warming)

    So my question which part of the Em spectrum(sun) is responsible for heating of the atmosphere ? Is it visible or infrared or both ?
  48. C

    Is Radio Wave Treatment of Water a Credible Solution for Agriculture?

    I hesitate to post this as it sure sounds like woo but it comes from an Irish University Prof. and appears to be endorsed by the Royal botanic gardens at Kew! Does anyone know of a peer reviewed paper...
  49. N

    Programs Can a Physics Major Make a Real-World Impact?

    I've been annoying myself with this buzzing in my head all summer and posting questions about what major to choose here almost every day! I'm so confused what to do when it comes to my major. I love physics and I'm taking AP Physics B online this year. I watch all these physics shows on TV all...
  50. S

    Sun & Global Warming: Does it Contribute?

    Does the sun contribute to global warming?