climate change

Pointing out that the weather always changes as some rebuttal to climate change is dumb and exemplifies how conservatives are dumb themselves and reduce things to the most simplest terms to try and understand them. Yes, the weather has always changed but it's the type of change and the frequency of the change that is concerning.

Here's an analogy that will hopefully explain climate change in different terms:

Imagine every hour you are given a number. After six hours you have been given these numbers in this exact order: 1, 2, 4, 8, 16, 32. Sure the numbers are changing, but they are changing at a consistent rate in an observable pattern (doubling - 1x2 = 2, 2x2=4, 4x2=8 and so on). Then, thirty minutes after receiving the number 32 you get the number 68. Not only did the frequency change (rather than receiving a number an hour after the previous one you received one half an hour after) but it doesn't follow the pattern (32x2=64, not 68). Then twenty eight minutes later you receive another number - 204. Again, the frequency changed and the pattern changed. Then fifteen minutes later you receive the number 816. The frequency and the pattern have changed again. Now imagine that the health of the Earth is all dependent on the original pattern of doubling the previous number. You'd want to figure out what is causing it and fix it right?

You can also really dumb this down like this: X and Y have a relationship. X and Y both increase at the same times and decrease at the same times. Humans start producing a lot of X and Y increases at the same rate as the increase in X. Over a period of ~120 years the level of X produced by humans is increasing exponentially and Y increases at a very similar rate. The increase in X is causing the increase in Y.

TL;DR - While temperature always fluctuates, there is no denying the Earth has been getting warmer over, as is evident below in Figure 13 below from NASA. While some of this can be contributed to natural factors, human activity has also contributed to the rise in temperature. We know this because certain gasses like carbon dioxide and other greenhouse gases (GHG) that result from the burning of fossil fuels have also become increasingly concentrated in our atmosphere and excessive concentrations of these gasses trap heat in the atmosphere.

Research Article from Environmental Research Letters - "Quantifying the consensus on anthropogenic global warming in the scientific literature"

• This research examines a massive amount of other peer reviewed literature - "11,944 climate abstracts from 1991–2011 matching the topics ‘global climate change’ or ‘global warming’" to be exact - and invited authors to rate their own papers. Among the self rated papers expressing a position on anthropogenic global climate change (AGW), 97.2% endorsed the consensus that human industry and agriculture are affecting Earth's atmosphere. Ultimately, the research concludes that "the number of papers rejecting the consensus on AGW is a vanishingly small proportion of the published research."

• The abstract states "Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming."

• Overwhelming scientific consensus that human activity is causing global warming (GW)/ anthropomorphic global warming (AGW): "Surveys of climate scientists have found strong agreement (97–98%) regarding AGW amongst publishing climate experts."

  • This consensus has been steadily growing, too: "Repeated surveys of scientists found that scientific agreement about AGW steadily increased from 1996 to 2009."

• More overwhelming consensus: "Among abstracts that expressed a position on AGW, 97.1% endorsed the scientific consensus. Among scientists who expressed a position on AGW in their abstract, 98.4% endorsed the consensus."

• In short, "The number of papers rejecting AGW is a miniscule proportion of the published research, with the percentage slightly decreasing over time. Among papers expressing a position on AGW, an overwhelming percentage (97.2% based on self-ratings, 97.1% based on abstract ratings) endorses the scientific consensus on AGW."

Study from EOS Science News by the AGCU (American Geophysical Union) - "Examining the Scientific Consensus on Climate Change"

• Finds that 90% of active publishers on climate change and 97% of climatologists who are active publishers on climate change believe "human activity is a significant contributing factor in changing mean global temperatures."

  • Figure 1 below charts the response to this question: "2. Do you think human activity is a significant contributing factor in changing mean global temperatures?"

Research Article from the Proceedings of the National Academy of Sciences of the United States of America - "Expert credibility in climate change"

• Ultimately finds that the large majority of publications and researchers are convinced by the evidence of anthropomorphic climate change (Figure 2).

  • "Preliminary reviews of scientific literature and surveys of climate scientists indicate striking agreement with the primary conclusions of the Intergovernmental Panel on Climate Change (IPCC): anthropogenic greenhouse gases have been responsible for 'most' of the 'unequivocal' warming of the Earth’s average global temperature over the second half of the 20th century."

  • "We show that the expertise and prominence, two integral components of overall expert credibility, of climate researchers convinced by the evidence of ACC vastly overshadows that of the climate change skeptics and contrarians."

Research/Data from NASA - "Scientific Consensus: Earth's Climate is Warming"

• NASA provides a list of statements from several scientific associations, agencies, organizations, publications, et cetera and their stances on global warming :

  • American Association for the Advancement of Science: "Based on well-established evidence, about 97% of climate scientists have concluded that human-caused climate change is happening."

  • American Chemical Society: "The Earth’s climate is changing in response to increasing concentrations of greenhouse gases (GHGs) and particulate matter in the atmosphere, largely as the result of human activities."

  • American Geophysical Union: "Based on extensive scientific evidence, it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. There is no alternative explanation supported by convincing evidence."

  • American Meteorological Society: "Research has found a human influence on the climate of the past several decades ... The IPCC (2013), USGCRP (2017), and USGCRP (2018) indicate that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-twentieth century."

  • American Physical Society: "Earth's changing climate is a critical issue and poses the risk of significant environmental, social and economic disruptions around the globe. While natural sources of climate variability are significant, multiple lines of evidence indicate that human influences have had an increasingly dominant effect on global climate warming observed since the mid-twentieth century."

  • The Geological Society of America: "The Geological Society of America (GSA) concurs with assessments by the National Academies of Science (2005), the National Research Council (2011), the Intergovernmental Panel on Climate Change (IPCC, 2013) and the U.S. Global Change Research Program (Melillo et al., 2014) that global climate has warmed in response to increasing concentrations of carbon dioxide (CO2) and other greenhouse gases ... Human activities (mainly greenhouse-gas emissions) are the dominant cause of the rapid warming since the middle 1900s (IPCC, 2013)."

  • U.S. Global Change Research Program: "Earth’s climate is now changing faster than at any point in the history of modern civilization, primarily as a result of human activities."

Also - Skeptical Science is a good resource for more regarding scientific consensus and other information about climate change.

Data from the National Oceanic and Atmosphere Administration (NOAA) - "Temperature Change and Carbon Dioxide Change"

• Identifies a "strong correspondence between temperature and the concentration of carbon dioxide in the atmosphere observed during the glacial cycles of the past several hundred thousand years." When the concentration of C02 increases, the temperature also increases and when the concentration of CO2 decreases, the temperature decreases (Figure 3).

• Climate change is not just reserved to changes in temperature: "paleoclimate data reveal that climate change is not just about temperature. As carbon dioxide has changed in the past, many other aspects of climate changed too. During glacial times, snow lines were lower, continents were drier, and the tropical monsoons were weaker. Some of these changes may be independent; others tightly coupled to the changing level of carbon dioxide."

Study from the Scientific Reports Journal - "On the causal structure between CO₂ and global temperature"

• In the abstract, the study states "Our study unambiguously shows one-way causality between the total Greenhouse Gases and GMTA. Specifically, it is confirmed that the former, especially CO₂, are the main causal drivers of the recent warming." Note that GMTA means global mean surface temperature abnormalities.

• The study identifies other literature which have confirmed human activity's influence on climate: "Recent updates based on multimodel analysis confirm that the primary components of external forcing over the past century are human-caused increases in greenhouse gases, stratospheric ozone depletion and change in atmospheric aerosol content, all reflecting human influence on climate."

• Among the results of the study are that it's analysis "unambiguously shows a one-way causality in the sense that the recent CO₂ increase is causing the temperature increase, but not the other way around."

• A certain data set in the study (Table 1), "clearly confirm that the total greenhouse gases (GHG), especially the CO₂, are the main drivers of the changing global surface air temperature."

  • This data set also shows that solar forces and volcanic eruptions don't signifgantly contribute to global warming: "Neither solar irradiance nor volcanic forcing contributes in a significant manner to the long-term GMTA evolution. This is true in spite of short episodes of volcanic forcing that are clearly visible in the time series as they are of insufficient strength to make significant long-term contributions to the GMTA dynamics."

• Ultimately the study concludes that there is a correlation and causality between human activity and global warming. It also concludes that natural forces like the sun and volcanic activity are not significant contributors to global warming.

  • "Using the IF concept we were able to confirm the inherent one-way causality between human activities and global warming, as during the last 150 years the increasing anthropogenic radiative forcing is driving the increasing global temperature, a result that cannot be inferred from traditional time delayed correlation or ordinary least square regression analysis. Natural forcing (solar forcing and volcanic activities) contributes only marginally to the global temperature dynamics during the last 150 years. Human influence, especially via CO₂ radiative forcing, has been detected to be significant since about the 1960s."

Research Article from the Science Journal - "Atmospheric CO₂: Principal Control Knob Governing Earth’s Temperature"

• Please note that I cite the full text on SciHub, as the publisher, American Association for the Advancement of Science, does not offer a free version of the full text.

• The abstract states "Ample physical evidence shows that carbon dioxide (CO2) is the single most important climate-relevant greenhouse gas in Earth’s atmosphere. This is because CO2, like ozone, N2O, CH4, and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does."

• The article asserts that CO2 is the main factor in climate change: "These studies established long ago that water vapor and CO2 are indeed the principal terrestrial GHGs. Now, further consideration shows that CO2 is the one that controls climate change."

  • "it is clear that CO2 is the key atmospheric gas that exerts principal control over the strength of the terrestrial greenhouse effect."

  • "There is telling evidence that atmospheric CO2 also governs the temperature of Earth on geological time scales"

• The article also identifies methane as a climate relevant greenhouse gas: "Methane is the second most important noncondensing GHG after CO2."

• The authors note that "The continuing high rate of atmospheric CO2 increase is particularly worrisome...and still the atmospheric CO2 control knob is now being turned faster than at any time in the geological record." Ultimately, "This makes the reduction and control of atmospheric CO2 a serious and pressing issue, worthy of real-time attention."

Research/Data from NASA - "Vital Signs - Carbon Dioxide"

• NASA defines carbon dioxide as "an important heat-trapping (greenhouse) gas, which is released through human activities such as deforestation and burning fossil fuels, as well as natural processes such as respiration and volcanic eruptions."

• Identifies that human activity, specifically human activity after the industrial revolution, has caused atmospheric concentrations of CO2 to be raised: "Over the past 170 years, human activities have raised atmospheric concentrations of CO₂ by 47% above pre-industrial levels found in 1850. This is more than what had happened naturally over a 20,000 year period (from the Last Glacial Maximum to 1850, from 185 ppm to 280 ppm)." This can be seen in Figure 4 below.

Research/Data from NASA - "Vital Signs - Global Temperature"

• Figure 5 below "illustrates the change in global surface temperature relative to 1951-1980 average temperatures. Nineteen of the 20 warmest years all have occurred since 2001, with the exception of 1998."

Research from Climate.gov from NOAA - "Climate Change: Atmospheric Carbon Dioxide"

• On carbon dioxide: "Carbon dioxide is a greenhouse gas: a gas that absorbs and radiates heat. Warmed by sunlight, Earth’s land and ocean surfaces continuously radiate thermal infrared energy (heat)...But increases in greenhouse gases have tipped the Earth's energy budget out of balance, trapping additional heat and raising Earth's average temperature."

• Data is provided which links human activity starting in the late 1800s as a consequence of the industrial revolution with rising CO2 levels (Figure 7). As CO2 emissions increase, the atmospheric level of CO2 increases as well.

  • "Human activities have increased the concentration of carbon dioxide in our atmosphere, amplifying Earth's natural greenhouse effect."

  • "The annual rate of increase in atmospheric carbon dioxide over the past 60 years is about 100 times faster than previous natural increases, such as those that occurred at the end of the last ice age 11,000-17,000 years ago."

• Figure 6 shows the increase of C02 in the atmosphere between 1975 - 2020, and relative to the data presented in Figure 5 from NASA, there is a clear connection between the increase in CO2 and rising global temperatures. The two graphs are overlaid atop one another so this connection can become more apparent in Figure 8.

  • Considering the relationship between CO2 and global temperature shown in Figure 3 and the recent relationship shown in Figure 8, it's undeniable that CO2 levels have an effect on global temperatures.

Research Article from Environmentcounts.org - "EC Perspective: Accounting for 800,000 years of climate change"

• This research article references the Vostok Antarctica ice core record - a collaborative ice drilling project between Russia, the United States, and France at the Russian Vostok station in East Antarctica in 1998 - to illustrate the relationship between temperature and CO2 levels (Figure 9). The study ultimately found that "There is a close correlation between Antarctic temperature and atmospheric concentrations of CO₂," according to the Carbon Dioxide Information Center, a part of the US Department of Energy Office. This article gives a similar description of the study's findings, stating that the study shows "a close correlation between Antarctica surface temperature and atmospheric CO2 concentration."

Research Article from Environmentcounts.org - "Close correlation of temperature and greenhouse gas concentrations over the last four glacial-interglacial cycles"

• Figure 10 is sourced from this research article. Like Figure 9, it relates to the Vostok Antarctica ice core record.

Research from the Geological Society of America - "CO2 as a primary driver of Phanerozoic climate"

• While this study does not deal solely with carbon dioxide's relation to temperature, it concludes that "There is a good correlation between low levels of atmospheric CO2 and the presence of well-documented, long-lived, and aerially extensive continental glaciations." So, the lower the amount of CO2 in the atmosphere, the colder it is. If it has been documented that low levels of CO2 correlate to long lasting glaciation (low temperatures), then it would be logical to assume higher levels of CO2 in the atmosphere would correlate to higher temperatures - basically what all this other literature asserts.

Research Article from the Proceedings of the National Academy of Sciences of the United States of America - "Human and natural influences on the changing thermal structure of the atmosphere"

• In the abstract, the research article states "We show that a human-caused latitude/altitude pattern of atmospheric temperature change can be identified with high statistical confidence in satellite data." Additionally: "Here, we present evidence that a human-caused signal can also be identified relative to the larger 'total' natural variability arising from sources internal to the climate system, solar irradiance changes, and volcanic forcing."

  • "Our results provide clear evidence for a discernible human influence on the thermal structure of the atmosphere."

• The article notes how similar combined human and natural external forces (ALL) and anthropogenic forcing only (ANT) are, suggesting that natural external forces have played a very little role in global climate change. Essentially, there is such a similarity between data from all presumed factors in global warming and anthropogenic factors

  • "The similarity of the ANT and ALL+8.5 fingerprints arises because model trends in atmospheric temperature over the past 30–60 y are primarily driven by anthropogenic influences, with only a small contribution from solar and volcanic forcing."

  • Figure 12 below showcases this, as the data under ANT (labeled as D in the figure) more closely matches the ALL model (labeled A in the figure).

• Ultimately, the study concludes that "Our results are robust to current uncertainties in models and observations, and underscore the dominant role human activities have played in recent climate change."

Research Article from the Proceedings of the National Academy of Sciences of the United States of America - "Identifying human influences on atmospheric temperature"

• This article ultimately finds that human activity has been the main external force in the shaping of climate: "We used a multimodel archive to obtain fingerprints of atmospheric temperature change. These fingerprints are estimates of the climate responses to external forcing by the combined effects of anthropogenic factors, volcanoes, and solar irradiance. The primary components of external forcing over the past century are human-caused increases in well-mixed greenhouse gases, depletion of stratospheric ozone, and changes in atmospheric burdens of various aerosol particles. Our fingerprints, therefore, mainly reflect human influences on climate."

• There is strong evidence in regard to human activity shaping and changing global climate: "Fingerprinting with atmospheric temperature changes has provided strong scientific evidence of a discernible human influence on global climate."

• Current climate change is best explained by human activity and cannot be explained by natural variability.

  • "The global-scale lower stratospheric cooling is primarily a direct radiative response to human-caused depletion of stratospheric ozone. Tropospheric warming is mainly driven by human-caused increases in well-mixed greenhouse gases. The multidecadal cooling of the stratosphere and warming of the troposphere, which is evident in all satellite datasets and simulations of forced climate change examined here, cannot be explained by solar or volcanic forcing, or by any known mode of internal variability."

• Essentially, this article asserts that human activity has a bigger fingerprint in shaping the current global climate than natural factors like volcanic eruptions or solar variability.

Research from the Intergovernmental Panel on Climate Change - "Summary for Policymakers"

• Finds that between 2000-2010 total human emissions of greenhouse gases like CO2 were the highest they've ever been: "Total anthropogenic GHG emissions were the highest in human history from 2000 to 2010"

  • 76% of these emissions where CO2 emissions which resulted from fossil fuel combustion and industrial processes: "CO2 emissions from fossil fuel combustion and industrial processes contributed about 78% of the total GHG emission increase from 1970 to 2010, with a similar percentage contribution for the period 2000–2010."

    • "CO2 remains the major anthropogenic GHG accounting for 76% of total anthropogenic GHG emissions in 2010."

    • Human activity is producing more and more CO2 emissions: "About half of cumulative anthropogenic CO2 emissions between 1750 and 2010 have occurred in the last 40 years."

Study from the Scientific Reports Journal - "On the causal structure between CO₂ and global temperature"

• In addition to identifying carbon dioxide as a significant factor in increasing temperatures, this study also set out to try and determine when human activity began to signifgantly influence global temperatures.

• As Figure 11 shows, human activity began to have a significant effect on global temperatures around the 1960s, an effect that has only increased to this day.

• Ultimately, the authors conclude that their study is "able to confirm the inherent one-way causality between human activities and global warming, as during the last 150 years the increasing anthropogenic radiative forcing is driving the increasing global temperature, a result that cannot be inferred from traditional time delayed correlation or ordinary least square regression analysis." The authors also identify that "Human influence, especially via CO₂ radiative forcing, has been detected to be significant since about the 1960s."

Research Article from Nature - "A search for human influences on the thermal structure of the atmosphere"

• Please note that I cite the full text on SciHub, as the publisher, Nature Publishing Group, does not offer a free version of the full text.

• This article from 1996 examines data from 1963-1987 and ultimately concludes that the changes in temperature over that time cannot be attributed to nature or natural circumstances.

  • "Our results suggest that the similarities between observed and model-predicted changes in the zonal-mean vertical patterns of temperature change over 1963-87 are unlikely to have resulted from natural internally generated variability of the climate system."

  • The articles abstract partially attributes this to human activity: "it is likely that this trend is partially due to human activities, although uncertainties remain, particularly relating to estimates of natural variability."