Science News article: ‘Case closed’: 99.9% of scientists agree climate emergency caused by humans

by Disillusioned JW 146 Replies latest social current

  • Rivergang
    Rivergang
    Interestingly, data had to be suppressed, indicating that "Earth's temperature hasn't risen for the last 15 years." I wonder why.

    Except that Daily Mail article which you quote above is dated September 2013 - i.e., it is nine years out of date.

    A lot has happened since then.

  • Vidqun
    Vidqun

    Joey jojo, global temperature anomaly 0.32 degrees Celsius above 1991-2020 global average. Higher for the decade, but compared to hundreds of years, nothing out of the ordinary. By the way, CO2 and carbon output have nothing to do with it. All to do with the big fellow up there. Polar ice has increased, so colder on the Poles. Polar bear population is also up.


  • Rivergang
    Rivergang

    So we have gone from “No temperature increase” to “The amount of temperature increase is of no consequence”?

  • Vidqun
    Vidqun

    Rivergang, I cannot find the place where I said "No temperature increase." Perhaps you can enlighten me. Are you quoting the Daily Mail-article perhaps? With demonstrated temperature fluctuations, one cannot say there is no temperature increase. I did say that CO2 is not the culprit. Actually, CO2 is essential for our survival. Here's a little diagram to illustrate:


  • Disillusioned JW
    Disillusioned JW

    Anoy Mous I am claiming the following.

    - The climate scientists are saying that if humanity does does not greatly reduce the CO2 outputs which come from burning of fossil fuels and if we don't change our habits of deforestation, then within about 30 years (or so, maybe within 20 years) the global temperature will be about 2 degrees Celsius higher than pre-industrial levls.

    - The climate scientists claim the global temperature is already about 1 degree Celsius higher than pre-industrial levels and that thus the global temperature is now already about one-half of the way to being 2 degrees Celsius above pre-industrial levels.

    - Though the charts presented by Vidqun on the surface seem to support his and yours claims about climate change, I am hesitant to agree with those claims, since I have seen other charts (and have read scientific articles) which give a very different impression. Furthermore, the chart called "Greenland GISP2 Ice Core -Temperature Last 10,000 Years" on its right hand side shows dates only up to 95 Years "Before Present" and thus excludes crucial recent data. That is because the chart presented by Vidqun excludes data from the most recent 167 years (not even just the most recent 95 years). That is because the year 2022 is 72 years after the year 1950 (and 95 + 72 equals 167), and 1950 is defined by scientists as "Present" when scientists use the term "Years Before Present", as documented below. During the last 100 years the global CO2 went up much higher than the prior 100 years. Scientists (primarily archaeologists and geologists) use the term "Before Present" in radiometric dating (such as Carbon14 dating) and they define that to mean "Before the year 1950 CE/AD". I learned that from science books. For documentation see https://en.wikipedia.org/wiki/Before_Present which says the following.

    "Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date (epoch) of the age scale. The abbreviation "BP" has been interpreted retrospectively as "Before Physics",[1] which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must now account for.[2][3]

    In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating .... Radiocarbon dating was first used in 1940. Beginning in 1954, metrologists established 1950 as the origin year for the BP scale for use with radiocarbon dating, using a 1950-based reference sample of oxalic acid."

    https://www.crowcanyon.org/education/learn-about-archaeology/archaeological-dating/ says the following. "B.P. (Before the Present) is the number of years before the present. Because the present changes every year, archaeologists, by convention, use A.D. 1950 as their reference. So, 2000 B.P. is the equivalent of 50 B.C."

    - Here are some science sources I use for inofmration about CO2 changes and their significant.

    >> https://climate.nasa.gov/rails/active_storage/disk/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdDVG9JYTJWNVNTSWhlVFIyTXpad2VtNW1ZM0pwWm01dGFUWjRhakF3Ykc1eFp6bG5hUVk2QmtWVU9oQmthWE53YjNOcGRHbHZia2tpZFdsdWJHbHVaVHNnWm1sc1pXNWhiV1U5SW1Odk1pMW5jbUZ3YUMwd09ETXhNakpmYzJOaGJHVmtYM05qY25WdVkyaGxaQzVxY0djaU95Qm1hV3hsYm1GdFpTbzlWVlJHTFRnbkoyTnZNaTFuY21Gd2FDMHdPRE14TWpKZmMyTmhiR1ZrWDNOamNuVnVZMmhsWkM1cWNHY0dPd1pVT2hGamIyNTBaVzUwWDNSNWNHVkpJZzlwYldGblpTOXFjR1ZuQmpzR1ZEb1JjMlZ5ZG1salpWOXVZVzFsT2dwc2IyTmhiQT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2tleSJ9fQ==--da2d254573b5caed3cd66f2d68ca7967d74913da/co2-graph-083122_scaled_scrunched.jpg has a grpah of of the carbon dioxide level from 800,000 years before 1950 up to the current day. NOtice the huge spike which took place after 1950 AD/CE and that is far higer than that going back to 800,000 years before the year 1950! Also notice the caption of "years before today (0 = 1950)".

    >> https://www.nature.com/articles/news051121-14 says the following.

    'Current levels of greenhouse gases in the atmosphere are higher than at any time in the past 650,000 years, say researchers who have finished cataloguing air bubbles trapped for millennia inside Antarctic ice. The record, which extends back over the past eight ice ages, shows that today's concentrations of carbon dioxide and methane far outstrip those in the past.

    Atmospheric carbon dioxide levels have risen 200 times faster over the past 50 years than at any other time during this period, says Thomas Stocker of the University of Bern, Switzerland, who led the analysis.

    The researchers studied air bubbles preserved in ice drilled from the Antarctic ice sheet as part of the European Project for Ice Coring in Antarctica (EPICA). The ice core represents a logbook of the state of the world's climate (see 'Frozen time') and goes back 210,000 years further than previous records.

    After searching ice spanning the period of 390,000-650,000 years before present, Stocker's team has discovered that carbon dioxide levels in the atmosphere did not exceed 290 parts per million during that time. Today, that figure is around 375 parts per million.

    The situation is similar for methane: during this period, levels hovered around 600 parts per billion. Today's atmospheric methane concentration is well over 1,700. Stocker and his colleagues report the results in Science1,2.

    Unprecedented push

    The burning of fossil fuels in the industrial era has pushed greenhouse-gas levels far beyond their natural fluctuations, says Stocker. "This is really something unprecedented," he says. Humans, by releasing fossil fuels from their imprisonment underground, are now adding greenhouse gases to the atmosphere on top of those released as part of natural climate cycles.'

    >> https://climate.nasa.gov/vital-signs/carbon-dioxide/ says the following.

    "Carbon dioxide (CO2) is an important heat-trapping gas, or greenhouse gas, that comes from the extraction and burning of fossil fuels (such as coal, oil, and natural gas), from wildfires, and from natural processes like volcanic eruptions. The first graph shows atmospheric CO2 levels measured at Mauna Loa Observatory, Hawaii, in recent years, with natural, seasonal changes removed. The second graph shows CO2 levels during Earth’s last three glacial cycles, as captured by air bubbles trapped in ice sheets and glaciers.

    Since the beginning of industrial times (in the 18th century), human activities have raised atmospheric CO2 by 50% – meaning the amount of CO2 is now 150% of its value in 1750. This is greater than what naturally happened at the end of the last ice age 20,000 years ago."

    >> https://climate.nasa.gov/vital-signs/global-temperature/ says the following.
    "This graph shows the change in global surface temperature compared to the long-term average from 1951 to 1980. Nineteen of the hottest years have occurred since 2000, with the exception of 1998. The year 2020 tied with 2016 for the hottest year on record since recordkeeping began in 1880 (source: NASA/GISS). NASA’s analyses generally match independent analyses prepared by the Climatic Research Unit and the National Oceanic and Atmospheric Administration (NOAA)."

    >> https://education.nationalgeographic.org/resource/climate-milestone-earths-co2-level-passes-400-ppm/ says the following.

    "On May 9, 2013, an instrument near the summit of Mauna Loa in Hawaii recorded a long-awaited climate milestone: the amount of carbon dioxide in the atmosphere there had exceeded 400 parts per million (ppm) for the first time in 55 years of measurement—and probably more than 3 million years of Earth history.

    The last time the concentration of Earth's main greenhouse gas reached this mark, horses and camels lived in the high Arctic. Seas were at least 30 feet higher—at a level that today would inundate major cities around the world.

    The planet was about 2 to 3 degrees Celsius (3.6 to 5.4 degrees Fahrenheit) warmer. But the Earth then was in the final stage of a prolonged greenhouse epoch, and CO2 concentrations were on their way down. However, the May 2013 reading represented something different. This time, 400 ppm was a milepost on a far more rapid uphill climb toward an uncertain climate future.

    ...

    The last time the concentration of CO2 was as high as 400 ppm was probably in the Pliocene Epoch, between 2.6 and 5.3 million years ago. Until the 20th century, it certainly hadn't exceeded 300 ppm, let alone 400 ppm, for at least 800,000 years. That's how far back scientists have been able to measure CO2 directly in bubbles of ancient air trapped in Antarctic ice cores.

    But tens of millions of years ago, CO2 must have been much higher than it is now—there's no other way to explain how warm the Earth was then. In the Eocene, some 50 million years ago, there were alligators and tapirs on Ellesmere Island, which lies off northern Greenland in the Canadian Arctic. They were living in swampy forests like those in the southeastern United States today. CO2 may have been anywhere from two to ten times higher in the Eocene than it is today."

    - Though it is true that many millions ago there were times when CO2 levels were much higher than today, it is important to note that much of what is currently dry land (including areas currently highly populated with humans in dense cities) was completely covered with ocean back then! The western and eastern sections of what is now called the USA (where the vast majority of the Democrats and political liberals of the USA live) was covered by ocean water back then. Maybe that is part of the reason why a much smaller percentage of Republicans and conservatives are concerned about climate change (including global warming) than Democrats and liberals are! Furthermore, more than 65 million years ago the continents were in very different locations that now, including at different latitudes are that had a major effect on the temperature of those land masses and sometimes compensating for much higher CO2 levels than present levels.

    - I very strongly disbelieve Vidqun's claim that "Polar ice has increased, so colder on the Poles" unless he/she is talking about during the cold seasons of the years. That is because science sources say that over a period of years the polar ice has been decreasing, not increasing.

    - I believe the above, since about 98% of the climate scientists have now become in agreement that humans are causing most of the recent changes in CO2 and thus most of recent changes of climate change, and that the climate scientists say action must be taken. I also believe the above because I have seen charts and simulations which back it up. Furthermore I recognize and accept that the climate scientists are far more of an expert on this matter than I, and that is another reason why I do not doubt what they say on that topic. I trust scientists' claims about science to a high degree, especially when there is overwhelming agreement among scientists in the relevant field pertaining to the particular scientific claim.

  • Disillusioned JW
    Disillusioned JW

    Science sources say that over a period of years the polar ice has been decreasing, not increasing. For example, https://www.nationalgeographic.com/science/article/arctic-summer-sea-ice-could-be-gone-by-2035 (Published August 13, 2020) says the following.

    "Last month, less sea ice covered the Arctic Ocean than in any other July since scientists began keeping track of it with satellites in 1979, marking another step toward a devastating and planet-reshaping inevitability: an ice-free summer for the Arctic Ocean.

    ... The Arctic is warming more than twice as fast as the rest of the planet, meaning that average temperatures have increased by about 3.5 to 5.5 degrees Fahrenheit (2 to 3 degrees Celsius) since the preindustrial period, compared to roughly 1.8 degrees F (1 degree C) for the planet as a whole. The change is accelerating, too: 0.75 degrees C of that warming have happened in the last decade."

    ... A study published this week in Nature Climate Change strongly reinforces predictions that summers in the northernmost sea are likely to lose their ice cover entirely by 2035—around the time a toddler today will graduate from high school.

    ... This year, an unprecedented Arctic heat wave, which researchers say was made at least 600 times more likely by human-caused climate change, sent air temperatures in Siberia above 100 degrees F, encouraged tundra fires to smolder there for months, and forced the collapse of Canada’s last remaining ice shelf off Ellesmere Island.

    It also drove sea ice around the Arctic to melt even faster than usual."

    See also https://www.usatoday.com/story/news/factcheck/2021/12/21/fact-check-arctic-antarctic-ice-didnt-reach-record-highs-2021/6503500001/ . It says the following.

    "Earth’s polar regions have lost enormous amounts of ice over the past few decades due to global climate change. However, some social media posts are claiming the opposite is true – that both Antarctic and Arctic ice have reached record levels.

    ... Experts say the land-based ice sheets at both of Earth’s poles have lost hundreds of billions of metric tons of ice over the past few decades. Arctic sea ice is in rapid decline, and Antarctic sea ice did not reach a peak in 2021.

    ... Arctic ice shrinking is a trend that goes back decades, according to records from NASA and the National Snow and Ice Data Center."


    Correction: In my prior post, in its third to last paragraph, I said the following. "Furthermore, more than 65 million years ago the continents were in very different locations that now, including at different latitudes are that had a major effect on the temperature of those land masses and sometimes compensating for much higher CO2 levels than present levels." Instead I should have said the following. 'Furthermore, more than 65 million years ago the continents were in very different locations than now, including at different latitudes and that had a major effect on the temperature of those land masses and sometimes compensating for much higher CO2 levels than present levels."

    Also in my prior post, where I said " I very strongly disbelieve Vidqun's claim that "Polar ice has increased, so colder on the Poles" unless he/she is talking about during the cold seasons of the years" I should have instead said the following. " I very strongly disbelieve Vidqun's claim that "Polar ice has increased, so colder on the Poles" unless he/she is talking about polar ice increasing during the cold season immediately following the the warm seasons during each 12 month period".

  • Vidqun
    Vidqun


    Sea ice depth data from the Polar Science Centre shows the Arctic has been thickening, a dimension measured in mm. 2022 is on course to be the thickest year since 2015. Sea ice depth saw the strongest regrowth in 44 years, with an 89mm expansion. Only 2011 saw a greater expansion at 90mm.


  • Disillusioned JW
    Disillusioned JW

    Vidqun, if you have a URL for your source please provide it.

    Your most recent post has a big error since you said "shows the Arctic" yet the illustration in your most recent post says "West Antarctica" and "East Antarctica". Arctic and Antarctica are totally different. The Arctic is at the North Pole and the Antarctic is at the South Pole.

    http://www.iau.gub.uy/?page_id=121&doing_wp_cron=1668804305.6326990127563476562500&lang=en says the following. 'The word Antarctica comes from the Greek language, antarktikos, which means “opposite to the Arctic”.' https://membean.com/roots/ant-opposite defines the prefix "ant-" as "opposite, against". Antarctica is thus not the same as Arctic nor even a part of the Arctic. Antarctica is located on the opposite side of the planet from the Arctic.

    https://climate.nasa.gov/ask-nasa-climate/2861/arctic-and-antarctic-sea-ice-how-are-they-different/ (dated April 10, 2019) says the following.

    "Arctic and Antarctic Sea Ice: How Are They Different?

    From NASA's Global Climate Change Website

    ... We often get questions from readers about Earth’s sea ice in the Arctic and the Antarctic, and the differences between those areas. Arctic sea ice has declined over the past five decades, while Antarctic sea ice has increased, and then declined. Why do they behave differently?

    How They’re Different

    The primary difference between the Arctic and Antarctica is geographical. The Arctic is an ocean, covered by a thin layer of perennial sea ice and surrounded by land. ("Perennial" refers to the oldest and thickest sea ice.) Antarctica, on the other hand, is a continent, covered by a very thick ice cap and surrounded by a rim of sea ice and the Southern Ocean.

    The Arctic Ocean is very deep and closely linked with the climate systems around it, making it more sensitive to climate changes than Antarctica.

    During the centuries of human exploration in the Arctic, sea ice covered the Arctic Ocean well year-round, up until recent decades. But satellite observations show that Arctic sea ice has been declining in extent*, thickness and volume since 1979.1 Average Arctic sea ice extent is at its lowest since 1850.

    During the summer melt season, the sea ice’s edge retreats toward the North Pole, only to re-grow during the Arctic winter. As a result of ongoing warming driven by human activities, the trend toward summer sea ice loss (from July to September, followed by a winter re-growth) continues.

    Recent research suggests that there is a relationship between Arctic sea ice losses and the human burning of fossil fuels in all months.2 Aerosols (tiny particles suspended in the atmosphere) tied to human activities have offset some of the Arctic sea ice extent loss trend; a reduction in aerosol pollution will likely see a sea ice loss acceleration.3 Ice loss at the sea ice’s margins** results in winds driving warmer water beneath the Arctic sea ice, increasing the amount of heat the Arctic Ocean stores 4 and priming conditions for further sea ice loss.

    ... Antarctic sea ice extent is currently below the long-term average of all decades prior since 1979. Previously, Antarctic sea ice extent had been above that long-term average due to long-term, large-scale wind circulation patterns that drove sea ice away from Antarctica5, making room for more sea ice to form nearer to the continent.6 Climate models, or computer simulations that incorporate all the factors that affect Earth’s climate, predicted this behavior.7 These long-term wind patterns reversed several years ago, resulting in a significant sea ice decline surrounding Antarctica. Values since then have been hovering around the average of all years prior in the satellite record. A figure showing current Antarctic sea ice extent can be found here.

  • Disillusioned JW
    Disillusioned JW

    Anony Mous please provide a URL, if possible, to back up your claim (stated on page 8 of this topic thread) of "... IPCC currently models a 1-1.5C temperature change by 2100 with a 2.5-3C in the worst case where everyone goes back to coal/wood burning. Oh, yes, since pre-industrial time. That is still more than 50 years off the prediction of the book and several degrees as well, depending on outcome."

    My understanding that the IPCC is not saying that current trends will limit global warming to only 1.5°C (above pre-industrial levels) by 2100. Instead the IPCC website says that humankind needs to take efforts to make sure that at 2100 global warming does not exceed 1.5 ºC (above pre-industrial levels) and that it looks like such will not be achieved. Notice that https://www.ipcc.ch/sr15/chapter/chapter-2/ says the following.

    "FAQ 2.1: What Kind of Pathways Limit Warming to 1.5°C and Are We on Track?

    Summary: There is no definitive way to limit global temperature rise to 1.5°C above pre-industrial levels. This Special Report identifies two main conceptual pathways to illustrate different interpretations. One stabilizes global temperature at, or just below, 1.5°C. Another sees global temperature temporarily exceed 1.5°C before coming back down. Countries’ pledges to reduce their emissions are currently not in line with limiting global warming to 1.5°C.

    ... This IPCC special report identifies two main pathways that explore global warming of 1.5°C. The first involves global temperature stabilizing at or below before 1.5°C above pre-industrial levels. The second pathway sees warming exceed 1.5°C around mid-century, remain above 1.5°C for a maximum duration of a few decades, and return to below 1.5°C before 2100. The latter is often referred to as an ‘overshoot’ pathway. Any alternative situation in which global temperature continues to rise, exceeding 1.5°C permanently until the end of the 21st century, is not considered to be a 1.5°C pathway.

    ... Countries that formally accept or ‘ratify’ the Paris Agreement submit pledges for how they intend to address climate change. Unique to each country, these pledges are known as Nationally Determined Contributions (NDCs). Different groups of researchers around the world have analysed the combined effect of adding up all the NDCs. Such analyses show that current pledges are not on track to limit global warming to 1.5°C above pre-industrial levels. If current pledges for 2030 are achieved but no more, researchers find very few (if any) ways to reduce emissions after 2030 sufficiently quickly to limit warming to 1.5°C. This, in turn, suggests that with the national pledges as they stand, warming would exceed 1.5°C, at least for a period of time, and practices and technologies that remove CO2 from the atmosphere at a global scale would be required to return warming to 1.5°C at a later date.

    A world that is consistent with holding warming to 1.5°C would see greenhouse gas emissions rapidly decline in the coming decade, with strong international cooperation and a scaling up of countries’ combined ambition beyond current NDCs. In contrast, delayed action, limited international cooperation, and weak or fragmented policies that lead to stagnating or increasing greenhouse gas emissions would put the possibility of limiting global temperature rise to 1.5°C above pre-industrial levels out of reach."

    The IPPC's assessment that the nations of Earth have not pledged enough to limit year 2100 global temperature to no more than 1.5°C above pre-industrial levels is very discouraging to me.

    Anony Mous I noticed that on page 7 of this topic thread you said the following. "I still want to see solutions promoted that don’t require thousands to die in order to minimize the human impact on the environment. I want to see sustainable solutions, that don’t require resources worse than oil." What gives you the impression that current proposed solutions require thousands of people to die? I am not aware of any environmental proposals which would require people to die. In contrast, I see that if humankind fails to halt global warming within a few decades then that will cause many millions of people to die!

    Vidqun I notice that on page 7 of this topic topic thread you said that wind turbines are not recycled. While that statement might be 100 correct it is now possible to recycle the wind turbines. https://www.energy.gov/eere/wind/articles/carbon-rivers-makes-wind-turbine-blade-recycling-and-upcycling-reality-support (in an article dated October 17, 2022) says the following.

    'Carbon Rivers, a company that produces advanced material and energy technologies, has commercialized a process to recover clean, mechanically intact glass fiber from decommissioned wind turbine blades. Glass fibers are a key part of the composite—a material made up of multiple constituents such as polymers and fibers—used to create wind turbine blades. Typically, turbine blades are 50% glass or carbon fiber composite by weight. However, Carbon Rivers upcycles all components of the blade, including the steel.

    ... A sustainable, circular economy for the wind energy industry means that materials that previously ended up in post-consumer waste streams can go directly into next-generation turbine blade manufacturing.

    ... Carbon Rivers is now in the process of separating part of its business into a stand-alone entity called Windfall Inc. which will develop the first full-scale U.S.-based glass fiber recycling facility. This is, however, not the only historic thing about the future Windfall plant: their site located outside Knoxville, Tennessee originally supported nuclear weapons production as part of the Manhattan Project.

    ... The planned facility is expected to process approximately 200 metric tons, or 5,000–7,000 fiberglass wind turbine blades each year, depending on blade size and generation. The recovered fiberglass can then be directed into new composites production.

    “With Carbon Rivers’ novel process, today’s decommissioned blades can become tomorrow’s wind turbine blades and electric vehicles,” Benson said.'

  • Disillusioned JW
    Disillusioned JW

    Vidqun I notice that on page 7 of this topic topic thread you said that wind turbines "have an approximate 15 year lifespan". That claim of yours seems to be correct for on the internet I see articles making claims ranging from 10 years to 25 years, including from information sources which I trust.

    I see news sources which I trust saying that wind turbines are piling up in landfills and that it is happening mainly because it is very hard to disassemble and/or cut/break the enormous modern turbine blades into smaller pieces for recycling in a way a that is economical. That is very discouraging to me. However there is some encouraging news. https://www.nrel.gov/news/program/2022/nrel-researchers-point-to-path-for-improved-wind-blade-recycling-rates.html (in an article dated Aug. 30, 2022) says the following.

    "Researchers at the National Renewable Energy Laboratory (NREL) are considering circular economy strategies to mitigate the impact of wind turbine blades at the end of their useful lifespan.

    The strategies are meant to address what to do with the blades once they are no longer needed, including using new materials that are easier to break down, extending their lifespan, and implementing various recycling options. Researchers at NREL have been investigating novel blade materials that are inherently more recyclable, thereby integrating solutions at the earliest stages of turbine component design."

    I notice that you made the claim of "By the way, one wind turbine cannot generate the amount of energy in its lifetime that was used in its manufacture." I am not convinced that one wind turbine cannot generate the amount of energy in its lifetime that was used in its manufacture. https://cleanpower.org/facts/wind-power/ makes a claim which disagrees with yours. It says the following.

    "Does it take more energy to make a wind turbine than the turbine will produce?

    No. It’s a common myth that it takes more energy to manufacture and build a wind turbine than the turbine will produce. In reality, a typical wind turbine will repay its carbon footprint in less than six months, and it will generate emission-free electricity for the remainder of its 20 to 30 year lifespan."

    https://www.forbes.com/sites/christopherhelman/2021/04/28/how-green-is-wind-power-really-a-new-report-tallies-up-the-carbon-cost-of-renewables/ has an article dated Apr 28, 2021,07:44am EDT. It says the following.

    'Building and erecting wind turbines requires hundreds of tons of materials — steel, concrete, fiberglass, copper, and more exotic stuff like neodymium and dysprosium used in permanent magnets.

    All of it has a carbon footprint. Making steel requires the combustion of metallurgical coal in blast furnaces. Mining metals and rare earths is energy intensive. And the manufacture of concrete emits lots of carbon dioxide.

    In the case of wind and solar power, those emissions are nearly all front-loaded. That contrasts with fossil-fueled electric power plants, where emissions occur continuouisly as coal and natural gas are combusted.

    ... Citing data from the likes of National Renewable Energy Laboratory, Vestas, Siemens Gamesa Renewable Energy, and Bernstein estimates, Venkateswaran determined that the biggest contributors to the carbon footprint of wind turbines are steel, aluminum and the epoxy resins that hold pieces together — with the steel tower making up 30% of the carbon impact, the concrete foundation 17% and the carbon fiber and fiberglass blades 12%.

    Good news: amortizing the carbon cost over the decades-long lifespan of the equipment, Bernstein determined that wind power has a carbon footprint 99% less than coal-fired power plants, 98% less than natural gas, and a surprise 75% less than solar.

    More specifically, they figure that wind turbines average just 11 grams of CO2 emission per kilowatthour of electricity generated. That compares with 44 g/kwh for solar, 450 g for natural gas, and a whopping 1,000 g for coal.

    ... Offshore wind turbines are becoming enormous, with General Electric’s GE Haliade X featuring blades 360 feet long and generating 14 megawatts. The carbon footprint of such monsters could get as low as 6 g/kwh.

    ...

    And they could be trending lower, thanks to the advent of so-called green steel. Swedish companies Hybrit and H2 Green Steel are investing billions to make millions of tons a year of green steel. Instead of burning metallurgical coal to fire a traditional blast furnace to reduce iron ore into pig iron, they will use green hydrogen electrolyzed via renewable power.

    They’re working as well on reducing the carbon footprint on the backend of wind and solar projects — by recycling old photovoltaic panels and turbine blades. "

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