151–160 of 189 posts
And second, the Earth might get greener as a result of climate change, and that those changes might not necessarily be what is best for Humanity.
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I doubt anybody really knows. It is well known that CO2 improves plants growth. It is also well known that plants grow better within a narrow band of temperatures. Increasing both the CO2 contents of the atmosphere and Earth's temperature will have some complex results where on the places within that temperature band, plants grow slightly faster, on places that cross from too cold into the band plants grow much faste…
These all seem like variables a robust computer model could account for, no?
The specifics of how trees react to increase CO2 concentration varies from one species to the other. AFAIK, only a few species have been measured, thus the increase on rate of growth on that component is quite uncertain. That can be improved by empirical tests, that many specializations of science are currently working into. Of course, the big elephant in the room here is ocean plankton, that has a two sided relation with CO2, because it both participates on photosynthesis and increases ocean acidity. AFAIK, there is little known on how those react.
Solar incidence is completely predictable, and doesn't tell a good story for global warming.
And for humidity, I don't think there is any reliable model out there. None of those are my specialization, so I may be wrong, but I don't think we have anything nearly viable for predicting this one.
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> plants love CO2 In artifical conditions in laboratory there is a significant effect, up to 20% when doubling pre-industrial CO2 concentration. But, in practice for wild plants nitrogen quickly becomes the bottleneck, so the real gains are much smaller. And even for farming plants (which have fertilizer providing additional nitrogen) the real gains diminish, and are more in 5-10% range. For some crops CO2 has very l…
I believe in global warming with all my heart but just to be balanced the heat also gives you a longer growing season and let’s plants thrive in higher latitudes. Edit funny the downvotes. I’m on your team guys! Just think we can’t ignore counter facts.
From what I understand, the increase in atmospheric carbon dioxide will have a massive greening effect on the Earth (plants love CO2). But it seems this fact is usually omitted so as not to complicate the intended message. I always found it ironic that the "eco" mode button in many cars is a leaf icon.
> it seems this fact is usually omitted so as not to complicate the intended message Any time a group starts altering the facts like this, it just shows that they value their 'message' above the truth, and they lose all credibility. Edit: Downvote = disagree, or people genuinely believe it's OK to lie to further your cause, I'm not sure what's more disturbing.
And also, the whole discussion branch nearby on the greening effect of small increases in CO2 is really missing the point, and is completely ungrounded in any science. There is a whole literature out there on how significant this effect is relative to other effects of rising CO2! (Spoiler: it is not that significant.)
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The CO2 Coalition is a pseudoscientific climate denial organization.
Perhaps rather than an ad-hominem you can instead argue the point being made?
CO2 is a gaseous fertilizer, providing carbon to plants. But anyone that has ever kept a garden, or even a potted plant, knows that plants also need water, plus nitrogen, phosphorous, and potassium (N-P-K). Hydroponics growers can add to that list [Mg++], [Ca++], [SO4--], [Fe++], [Mn++], [Zn++], [Cu++], [BO3---], [MoO4--], and [Cl-] ions, usually present in the soil that is not used in a hydroponics system.
So increasing CO2 has diminishing returns, until further increase results in no further plant growth.
Earlier quoted context omitted.
I doubt anybody really knows. It is well known that CO2 improves plants growth. It is also well known that plants grow better within a narrow band of temperatures. Increasing both the CO2 contents of the atmosphere and Earth's temperature will have some complex results where on the places within that temperature band, plants grow slightly faster, on places that cross from too cold into the band plants grow much faste…
These all seem like variables a robust computer model could account for, no?
Earlier quoted context omitted.
Okay, here's the thing: If you have plants with more or less CO2 under otherwise the same conditions you'll have more growth in the plants. However that's not how the planet works. If you put more CO2 in the atmosphere you'll have for example rising sealevels and larger deserts (and probably more effects that diminish food production). You can't just pick a single effect of increased CO2 in isolation. (Except of cour…
ELI5: how will melting ice caps cause rising sea levels? Ice has higher volume than water it's made of, so the effect of ice melting should be sea level falling. At least that's the case of Arctic Sea, which is just this: frozen sea. Antarctic is different, because most of the ice is located on land, above the sea level. But then, shouldn't northern cap melting cancel out melting of the south one?
As it happens, seawater is denser than pure water, with a density averaging 1.088 g/mL, so if we were just talking about floating ice, 1 kg of floating ice would displace 1 kg of seawater, with a volume of 0.919 L, when the ice (mostly-pure water) melts, it supplies additional volume of 1 L, an increase of 8.8% over the submerged volume of the ice. This mixes with the saltwater to reduce salinity and lower the density, but the overall effect is a slight rise in water level.
Now forget about floating ice. Some ice is not floating. It rests upon surface rock. When it melts, 100% of its volume (eventually) flows down into the ocean. When land-ice melts, it has a far greater impact on sea level. But we only need to worry about land ice that rarely melts due to seasonal variation: ice found mainly in the glaciers and icepack on Greenland and Antarctica. Due to albedo and insulation effects, it is more difficult to melt land-ice than sea-ice, but it is indeed melting at rates unprecedented within the relatively short span of human observations.
(If a land-ice glacier calves an iceberg into the ocean, the immediate effect is to raise sea level by about 86% of the volume of the ice, with additional rise occurring as the ice melts.)
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These kinds of comments damage the quality of discourse on HN.
Besides which, it's the ongoing fake brouhaha about "Russian collusion" that has already guaranteed Trump's reelection. Regular people don't believe that BS anymore, and they will remember it, no matter how savagely the Ds attempt to discredit the theoretically-soon-to-be-released Mueller report. If Ds had just moved on to important matters, Trump would have little hope, but as it is he will appear to be the adult in…
So is it a net gain or not?
> “When the greening of the Earth was first observed, we thought it was due to a warmer, wetter climate and fertilization from the added carbon dioxide in the atmosphere, leading to more leaf growth in northern forests, for instance. Now, with the MODIS data that lets us understand the phenomenon at really small scales, we see that humans are also contributing.” That global warming may induce more agriculture, and fo…
There was a 200 page report on global warming from the 1980s on HN a few days ago which had several sections on this as upsides to global warming. I only read 50 pages of it, but it is a remarkably clear and level headed document.