4 ms·

https://www.nytimes.com/2018/07/30/science/climate-change-plants-global-greening.html https://www.nytimes.com/2018/07/30/science/climate-change-pl... "Despite

by acqq 8y ago

https://www.nytimes.com/2018/07/30/science/climate-change-plants-global-greening.html https://www.nytimes.com/2018/07/30/science/climate-change-pl... "Despite global greening, carbon dioxide levels have climbed over the past two centuries to levels not seen on Earth for millions of years. And the carbon dioxide we’ve injected into the atmosphere is already having major impacts across the planet." The "global greening" effect, to the amount it can manifest itself, existed since the CO2 started to increase but we still see that the problems from higher CO2 increase and will get always bigger. It won't save us from any problems made by global warming.

marcus_holmes 8y ago
I kinda find it weird, though. Because we only know what prehistoric climate conditions were because of tree rings (and ice cores, but they're measuring different things). So predicting future tree ring growth based on climate changes, when we estimate the historical climate based on tree ring growth, means we can make up any relationship we want.
- acqq 8y ago
  That shows lack of understanding in purpose and use of the tree rings and it is not relevant to the topic. What I read from your statements is just that you don't understand how the past climates are scientifically reconstructed, and want to express the doubt in the results of all the work of all the scientist that agree (which is effectively all of them, minus the ones directly or indirectly funded by fossil fuel companies or motivated by political relations, if you have other impression, it's distorted by the intentional activity of said companies and political groups). But we don't configure the current modeling systems at all using the "prehistoric" reconstructions, the models and the currently measured values are much more precise. The "prehistoric" reconstructions only give you something to compare the orders of magnitudes. And comparing that, the warming is unprecedented. Which is not surprising giving that the humanity managed to extract and burn more then the half of all readily available oil from the Earth's crust in just 100 years. That very oil in the crust is however a result of more than 4 billion of years of the Earth's existence. If you’re reading this in some country like US, given that the average US car weights around 2 tonnes, your existence alone is probably responsible for the CO2 mass equivalent to the weight of 7–10 cars every year, and to the volume of CO2 which corresponds to the volume of more than 3000 cars. And the CO2, even if it's invisible for us, is actually "black" for something important: it's blocking the part of the spectrum that would allow the Earth surface to cool off. That's how small concentrations of it, compared to some other stuff in the air, produce such a big effect. The physics is simple and undeniable, and it's known that there will be always more problems caused by the growth of CO2 in the atmosphere which increases the surface temperature of the Earth.
  - jessaustin 8y ago
    ...more then the half of all readily available oil from the Earth's crust in just 100 years. We've been hearing this Peak Oil crap for years. Maybe eventually it will be true...
  - marcus_holmes 8y ago
    Past climates are scientifically reconstructed from data recovered from physical objects that were present during those climates. One of the main sources, if not the main source, for that data is tree rings from old wood. If this statement is untrue, in any way, then please correct me, because yes, I've misunderstood how past climates are scientifically reconstructed. But I'm going to need you to explain what data is used during their reconstruction (and not some hand-wavy "it's very difficult and not for non-climate-scientists to understand").
    - acqq 8y ago
      Tree rings are absolutely used as a proxy to infer the past, the science is called dendrochronology, and the application of it is called https://en.wikipedia.org/wiki/Dendroclimatology https://en.wikipedia.org/wiki/Dendroclimatology The limitations of it are known, and you won't find that the results of it are used for false claims by the real scientists: https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapter05_FINAL.pdf https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapt... What I'm posting above is the real report by the The Intergovernmental Panel on Climate Change. If you look in the context, tree rings are just one piece of the big and complex picture. See my other comment for an example how those who just try to confuse simply ignore (and don't even care for) geological facts when they try to push their agenda. The same happens with those who try to sell you the doubt and false claims about the state of climate research. The scientifically known uncertainties in using the tree rings as proxies aren't changing any facts about the reality of global warming. It's undeniable basic physics. CO2 makes the Earth surface warmer because it blocks the part of the spectrum that would otherwise allow it to cool off. The part of the spectrum of the Sun that warms the surface up is however not blocked by the CO2. So the Earth gets the same effect that you have when you cover yourself with a blanket. It's warmer under it. It's undeniable and we are observing the effects every day: https://tidesandcurrents.noaa.gov/publications/techrpt83_Global_and_Regional_SLR_Scenarios_for_the_US_final.pdf https://tidesandcurrents.noaa.gov/publications/techrpt83_Glo... If we don't do anything the expected sea rise on US shores is estimated up to 2.5 m higher (8 feet) in 2100. The non-red lines in the graphs are for the scenarios if the humanity actually stops pushing CO2 in the atmosphere very soon. We're already not following the "blue" strategies.

by acqq 8y ago

marcus_holmes 8y ago

I kinda find it weird, though. Because we only know what prehistoric climate conditions were because of tree rings (and ice cores, but they're measuring different things). So predicting future tree ring growth based on climate changes, when we estimate the historical climate based on tree ring growth, means we can make up any relationship we want.

acqq 8y ago
That shows lack of understanding in purpose and use of the tree rings and it is not relevant to the topic. What I read from your statements is just that you don't understand how the past climates are scientifically reconstructed, and want to express the doubt in the results of all the work of all the scientist that agree (which is effectively all of them, minus the ones directly or indirectly funded by fossil fuel companies or motivated by political relations, if you have other impression, it's distorted by the intentional activity of said companies and political groups). But we don't configure the current modeling systems at all using the "prehistoric" reconstructions, the models and the currently measured values are much more precise. The "prehistoric" reconstructions only give you something to compare the orders of magnitudes. And comparing that, the warming is unprecedented. Which is not surprising giving that the humanity managed to extract and burn more then the half of all readily available oil from the Earth's crust in just 100 years. That very oil in the crust is however a result of more than 4 billion of years of the Earth's existence. If you’re reading this in some country like US, given that the average US car weights around 2 tonnes, your existence alone is probably responsible for the CO2 mass equivalent to the weight of 7–10 cars every year, and to the volume of CO2 which corresponds to the volume of more than 3000 cars. And the CO2, even if it's invisible for us, is actually "black" for something important: it's blocking the part of the spectrum that would allow the Earth surface to cool off. That's how small concentrations of it, compared to some other stuff in the air, produce such a big effect. The physics is simple and undeniable, and it's known that there will be always more problems caused by the growth of CO2 in the atmosphere which increases the surface temperature of the Earth.
- jessaustin 8y ago
  ...more then the half of all readily available oil from the Earth's crust in just 100 years. We've been hearing this Peak Oil crap for years. Maybe eventually it will be true...
- marcus_holmes 8y ago
  Past climates are scientifically reconstructed from data recovered from physical objects that were present during those climates. One of the main sources, if not the main source, for that data is tree rings from old wood. If this statement is untrue, in any way, then please correct me, because yes, I've misunderstood how past climates are scientifically reconstructed. But I'm going to need you to explain what data is used during their reconstruction (and not some hand-wavy "it's very difficult and not for non-climate-scientists to understand").
  - acqq 8y ago
    Tree rings are absolutely used as a proxy to infer the past, the science is called dendrochronology, and the application of it is called https://en.wikipedia.org/wiki/Dendroclimatology https://en.wikipedia.org/wiki/Dendroclimatology The limitations of it are known, and you won't find that the results of it are used for false claims by the real scientists: https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapter05_FINAL.pdf https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapt... What I'm posting above is the real report by the The Intergovernmental Panel on Climate Change. If you look in the context, tree rings are just one piece of the big and complex picture. See my other comment for an example how those who just try to confuse simply ignore (and don't even care for) geological facts when they try to push their agenda. The same happens with those who try to sell you the doubt and false claims about the state of climate research. The scientifically known uncertainties in using the tree rings as proxies aren't changing any facts about the reality of global warming. It's undeniable basic physics. CO2 makes the Earth surface warmer because it blocks the part of the spectrum that would otherwise allow it to cool off. The part of the spectrum of the Sun that warms the surface up is however not blocked by the CO2. So the Earth gets the same effect that you have when you cover yourself with a blanket. It's warmer under it. It's undeniable and we are observing the effects every day: https://tidesandcurrents.noaa.gov/publications/techrpt83_Global_and_Regional_SLR_Scenarios_for_the_US_final.pdf https://tidesandcurrents.noaa.gov/publications/techrpt83_Glo... If we don't do anything the expected sea rise on US shores is estimated up to 2.5 m higher (8 feet) in 2100. The non-red lines in the graphs are for the scenarios if the humanity actually stops pushing CO2 in the atmosphere very soon. We're already not following the "blue" strategies.