What is Climate change: Definition and 119 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. S

    Earth thermal feedback effects

    Looking at some apparently widely accepted data, I understand: - CO2 mass change => direct "greenhouse" heating is approx linear over ranges considered - Doubling CO2 (i.e. adding same again) would give 1C change for direct greenhouse. - CO2 change x1.5 since pre-industrial times (half added)...
  2. 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...
  3. kuruman

    What is the Potential for Clean Energy Development According to Schwarzenegger?

    Our Governator is attending the Austria world initiative on climate change. He wants us to know that we have "2000 Gigabytes of clean energy" waiting to be developed if only the permit process can be expedited. Lucky us. Listen to the video at about t = 2:20 and rejoice...
  4. B

    Will charcoal (carbon) oxidize in the air?

    Wikipedia — Carbon sequestration claims that burying charcoal into the soil offsets CO2 and thus reduces the greenhouse effect: Is it a must to cover charcoal/biochar with the soil to prevent the air and rain water exposure to avoid oxidation, i.e. offset carbon dioxide? Would it otherwise...
  5. S

    Consequences of global climate change

    It is known, that due to global warming, the average temperature on Earth over the past 100 years has increased by 1.2 degrees. At the same time, I heard that earlier the temperature of the Earth was 7 degrees higher than the current one. I do not deny the danger of global warming, because I...
  6. anorlunda

    Viral spillover risk increases with climate change in High Arctic lake

    https://royalsocietypublishing.org/doi/10.1098/rspb.2022.1073 This raises the specter of pre-human era pathogens being re-released because the permafrost is melting. AFAIK, even the sci-fi authors have not explored that idea.
  7. M

    Does climate change affect air density at altitude (scale height)?

    Increases in global temperature change affect the tree line and presumably comfortable habitability via temperature, and average air pressure associated with weather patterns. That's not what I mean. I'm thinking a 1/50 increase in kelvin temperature might increase the scale height of Earth's...
  8. kadiot

    Can climate change trigger earthquakes?

    I joined Dystopia Manila anthology book project. It’s a collection of one-shot stories with two very important elements: 1. A climate change crisis that humans failed to address; and 2. A dystopian, sci-fi story that is set in a futuristic Metro Manila I'm wondering if climate change triggers...
  9. M

    Historic CO2 levels, climate change

    Not trolling here, just have genuine confusion over CO2 levels comparied to what we believe CO2 levels have been historically and their effect on climate change. I recently saw some Facebook group infographic posts which claimed that CO2 concentration in the atmosphere is the lowest it has ever...
  10. A

    Climate skeptics according to faculty and/or degree?

    I'm looking for a survey, research or some statistics that shows in which university faculty climate skeptics are more or less present. Same for level of degree. I found only some according to the political orientation but nothing about the above. Did I miss something? If so, can you please...
  11. Astronuc

    Drought (possibly 'climate change') and famine 2200-2000 BCE

    Like the thread on Earthquakes possibly contributing to the collapse of civilizations in the last Bronze Age, I heard that a famine impacted Egypt, and possibly the Aegean region and perhaps into Eastern Europe and parts of North Africa during the period 2200 - 2000 BCE (aka Early Helladic III...
  12. Amrator

    Other Books on the Physics of Climate Change

    Hello, I'm looking for a textbook on climate change that is not afraid to use advanced physics and mathematics (thermal/statistical physics, differential equations, fluid dynamics, etc.). Too many textbooks on the topic shy away from the mathematics, preventing me from obtaining a deep...
  13. C

    Today's Climate Change and the Permian-Triassic Boundary

    This video shows how geologists figured out that a huge greenhouse effect nearly wiped out life on Earth 250 million years ago. The explanation is premised on an analysis of rock samples found at the Permian-Triassic Boundary in Utah. It involves a lot of Chemistry and Earth science so I...
  14. BillTre

    How will climate change affect the US?

    Several maps, from ProPublica, showing how climate change may play out as changes in the US. Lessor amounts of similar data can be found in this PNAS publication. Some of the maps are interactive (different levels of continued emissions). The maps cover: temperature/humidity based most...
  15. G

    Negative carbon emissions to fight ocean acidification?

    The IPCC report strongly encouraged not only trying to get our carbon dioxide emissions down to fight climate change, but to go into negative emissions so as to draw the carbon dioxide out of the air (since it's too high as it is). Wouldn't that help to fight ocean acidification too? Because...
  16. D

    Hapgood’s Crustal Slip Hypothesis

    Possible Evidence Contrary to Hapgood’s Crustal Shift Hypothesis While keeping an open mind, I am sceptical about Hapgood’s theory for the following reason:- On the Australian continent there exists the longest “unbroken” chain of volcanoes in the world which is due to the passage of the...
  17. D

    Can someone please debunk this claim that CO2 does not trap heat?

    Hi everybody I follow climate denier pages and every now and then come across a claim that doesn't seem to have been debunked yet. One such claim is made here: <link to uacceptable source deleted> The gist of the article is that scientists experimented with using different gases in double...
  18. A

    Are orbital sun shades to reverse climate change realistic?

    I'm referring to proposals that suggest putting large reflective surfaces at the L1 Lagrange point. I've also been thinking of something like capturing a nearby asteroid and turning it into an artificial ring at the equator or dumping lots of small infrared reflecting particles or releasing...
  19. BillTre

    How can we engineer corals to better adapt to climate change?

    Here is a long Science magazine News article on trying to engineer corals to better deal with climate change. Two challenges corals face due to climate change: increasing the temperature of the water in which coral lives (A 2˚ C temperature increase is said to be deadly to most coral) as...
  20. B

    Earth’s magnetic field alignment and climate change?

    The Earth’s magnetic field is slowly moving with respect to the Earth’s surface and to the Sun’s incoming radiation and solar wind direction. Does the tilting/moving of Earth’s magnetic field axis to the incoming solar wind direction change the protection on different points of the Earth’s...
  21. 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...
  22. W

    Maunder Minimum & Climate Change

    We all know that our CO2 emissions will warm the planet. However I am wondering to what extent do climate models include the view that we might be heading to a new Maunder Minimum? https://www.nextbigfuture.com/2018/11/winter-is-coming-super-grand-solar-minimum.html Will this buy us a bit more...
  23. D

    Ocean acidification and atmospheric carbon

    Hi everyone The following graph shows levels of CO2 in the oceans increasing with atmospheric CO2. https://ocean.si.edu/conservation/acidification/ocean-acidification-graph Given that global temperatures should rise with CO2, is it theoretically possible for the oceans warm to the point...
  24. D

    B What would happen to Earth's temperatures without an atmosphere?

    Hi everyone I've read that if Earth had no atmosphere it'd be completely frozen over with temperatures around 255K. Why is this the case when the moon has daytime temperatures of 373K (and night time temperatures of 100K)? Why wouldn't the oceans thaw during the day? Are they just too big...
  25. hagopbul

    Are there other variables that control climate change?

    Hello all It's been a while ,as I read the almost daily news on climate change , some question come up to my mind , dose the ionosphere has any effect on climate change , as we all know now the Earth magnetic field is weakening ,and the temperature is rising ,dose this two variables related to...
  26. Posty McPostface

    Will climate change stimulate or harm the economy?

    I'm reading about the parable of the broken window, which states: I was wondering if this can be related in some way to climate change as a whole. My reasoning is that given that climate change is a consequence of a lack of knowledge about the sum total negative and positive externalities of...
  27. Posty McPostface

    What does inaction about existential threats tell us about....

    What does inaction about existential threats tell us about ourselves? Take for example climate change or the lack of any action to mitigate potentially civilization ending asteroid impacts? Is this simply an issue related to our very way of being? And, if so what can be done about it?
  28. Posty McPostface

    Arguing with economics (economists)

    And with a conservative for the matter... How do you argue with economics? Let's take the example of fossil fuel production. If fossil fuels get the job done cheaper (in terms of energy production) then the common sense thing to do is to invest in fossil fuels, such as by expanding offshore...
  29. M

    Climate Change: Why Doesn't Rising Temperature Balance Out?

    First, I am not a scientist, so this may be a stupid question. But with all the concern about global warming - and given that temperature and pressure are related - why doesn’t rising temperature cause the atmosphere to expand outward and the temperature to fall as a result, back to an...
  30. P

    Can Economics be guided by science?

    In economics, Adam Smith coined the term (rather unintentionally) 'the invisible hand' of economics that drives all the efficiency gains and progress entailed by using the market to mediate and satisfy human wants and needs. The rather recent advent of the market entity has led to enormous...
  31. Solomei

    Tracking Earth's Climate Change: Recent Data and Observations

    Im quite fascinated over how Earth is constantly trying to stabilise itself. What is your most interesting observation or 'happening' about climate change?
  32. R

    Is a Master's in Carbon Management Enough to Pursue a PhD in Geophysics?

    Hi everyone, I'm currently doing an MSc in Carbon Management at the University of Edinburgh, and have decided that I enjoy the geophysics aspects (renewable energies, etc.) more than the economics/policy aspects in which I have undergraduate experience. Given this, I'd like to pursue a PhD in...
  33. Ackbach

    MHB Climate Change and Bias Amongst the Climate Scientists?

    Firstly, and most importantly: I am not interested in getting into a debate about climate change in this thread. If you try to engage in debate with me in this thread, I will immediately abuse my administrative powers and physically delete your post! (Devil) Secondly, I want to make it clear...
  34. 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...
  35. jedishrfu

    XKCD's "Climate Change Timeline" | See History's Impact

    XKCD made a really cool Climate Change timeline: https://xkcd.com/1732/ which shows the effect humanity has had on it vs history.
  36. R

    Logical steps of climate change

    There are two ideas: (1) C02 is increasing. (2) The global temperature is increasingI am looking for the specific mechanism (most likely an equation / theories of physics) which climate scientists use to connect (1) and (2) together, and infer that (1) causes (2). I am looking for the math /...
  37. pioneerboy

    A Climate change and changes in astronomical viewing conditions....

    I'd like to read some articles, papers, or whatever scientific there is about the prospects and impacts of climate change for professional ground based astronomy and observatory sites. In particular, which locations which are now among the most suitable sites for observatories - especially...
  38. Zephyr007

    Is climate change on other planets affected by similar cycles?

    I didn't expect that this year will be too hot here in the Philippines... D: Welp... Here's an update :https://web.pagasa.dost.gov.ph/index.php/climate/climate-advisories Is climate change taking effect here? I guess so. Will somebody care for an ice cream? lol
  39. fredey

    What would happen if? you heatsink earth and space

    It is a thought I just thought of with all the wonderful attention that climate change has been getting recently. The thought goes as follows: The world has ever increasing entropy as the whole universe has so. With humans adding to this effect even if green house gases curbed due to this...
  40. 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...
  41. Kior

    Why has CO2 decreased in the history of the Earth?

    I noticed that the Co2 is actually decreasing in the Eon time. My guess is lush vegetations or forests began to grow which absorbed the Co2 by photosynthesis? Would anyone give me any clue?
  42. U

    How much will the atmospheric carbon dioxide change?

    Homework Statement Suppose ##10^{14} kg## of carbon dioxide was released into the atmosphere and absorbed completely, what is the percentage change of carbon dioxide concentration? Take initial atmospheric mass mixing ratio to be ## 5.7 \times 10^{-4} kg/kg##. Homework EquationsThe Attempt at...
  43. D

    Is climate change still debated?

    My current understanding is that civilization is built on fossil fuels, and the resulting emissions cause climate change. I'm wondering if anyone still has worthwhile arguments against this view, or whether there really is a debate. I currently consider the following reference to be the most...
  44. .Scott

    Can Reducing Carbon Emissions Have a Significant Impact on Sea Level Rise?

    I've certainly hear and read tons of stuff that is not only less than top notch science, but also seems to answer the wrong questions. What I am specifically interested in are scientific cases presented - not for how much damage we are experiencing or will experience - but what good it would...
  45. phyzguy

    Ice Age Modeling: Major Step Forward in Climate Change?

    OK, I'll dive in and start a climate change thread. I'm fascinated by the Nature paper by Abe-Ouchi, et.al., which I already uploaded in post #21 of this thread. If you look at Figure 1, the model does an outstanding job of modeling the last several ice ages. I have been somewhat skeptical of...
  46. 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
  47. 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...
  48. A

    Atmospheric Emission: Climate Change, CO2 & Quantum Chemistry

    A friend is a quantum chemist. He is in agreement that climate change is bad (he feels the primary problems with CO2 is ocean acidification). Anyway he states there is no credible research showing that atmospheric CO2 re-emits radiation to the planet. His belief is that the intersection of IR...
  49. T

    B.S. in EE trying to transition into a renewable energy career

    I'm currently on a career path I got into through an applied physics masters, but there isn't much of future in my particular field so I'm trying to switch. Additionally, I'm very concerned about climate change and I have a B.S in Electrical Engineering (with a minor in physics), so I'm...
  50. J

    Coriolis effect and base forces

    I wonder if anybody can point me to a good explication of the atmospheric Coriolis effect broken down into base forces. Most of the explanations I've seen are problematic, even flawed as far as I can tell, and they rarely talk about force vectors. I've seen demonstrations, for instance a...