New answers tagged climate-change
2
Climate Change definitely seem like a vicious cycle on a decadal scale. As other answers have pointed out there are numerous positive feedbacks such as:
Warmer atmosphere holding more water vapor (which is a GHG) leading to more clouds
Reduced snow cover reflecting less solar radiation (lower albedo)
Reduced snow and ice cover on land leading to faster ...
0
CO2 is dark in the longwave infra red wavelenght so the higher the consentration is the darker the atmosphere will be in this wavelenght.and as you probably know darker colours absorb more heat.
CO2 is not a very powerful greenhouse gas but the amount of it in our atmosphere make this effect the dominating source for the heating we can see today.
Lots of ...
0
It can, but it's not very helpful. A large number of gasses (methane being one) decompose relatively quickly in the atmosphere to form other compounds. A longer time horizon means you capture all of that change in the metric (as compared to CO2), while if you did it for a day you'd end up with a figure that only really made sense for that day. The details of ...
-6
It isn't Co2 (sorry I know that's likely unpopular for most to hear), it's (primarily) the sun.
Real quick, rising Co2 doesn't cause wildfires, trees love Co2, visit a greenhouse. Wildfires are a result of (bleep holes) running around lighting fires. Look it up, nearly 200 people arrested so far in Australia for arson.
Ocean rise prediction data (focused ...
10
Borrowing an explanation from one of my other answers, the basic mechanism of the greenhouse effect is roughly as follows (note this is also a simplified model)
The Earth is in (to all intents and purposes) a vacuum, so it can only
gain or lose heat via radiation. The sun emits most of its radiation
at visible and UV wavelengths. The Earth's ...
4
I would say that the reason is because human civilisation, and particularly agricultural practices, evolved and are adapted to the pre-industrial climate. This means that any substantial change in the climate will require changes in our civilisation and agriculture, which inevitably has a cost. So the reason that most of the changes are negative is not to ...
2
Urban areas, where most snow clearing is done, are heat islands already, so it would be tough to disentangle the effect of clearing snow off roads. Whitewashing black asphalt is one of the strategies being tried to reduce the heat effect in the summer, though, and black asphalt is seen as a big factor in heat islands, so it seems reasonable that exposing ...
40
There are indeed a lot of positive feedback mechanisms, i.e. a warm climate leads to a warmer climate. From this Wikipedia article, they are:
Carbon cycle feedbacks
Cloud feedback
Gas release
Ice-albedo feedback
Water vapor feedback
However, there are also a few negative feedbacks (same source):
Blackbody radiation
Carbon cycle
Lapse rate
Impacts on ...
22
You've correctly identified a number of individual mechanisms which form "vicious circles". They're more formally known as "positive feedbacks". As you've noted, loss of albedo (reflectivity) from melted ice is one. Some of the others you've listed are a bit more complex - e.g. trees will regrow, algae in oceans are quite effective at removing CO2, etc.
One ...
-2
Yes, you are quite right, it does create a vicious circle, though not quite as vicious as some might think. As you suggest, there are natural forces which ameliorate the effects of this vicious circle.
Most of the woodland burned by these fires regenerates, though this takes a while. Where it doesn't regenerate, its place is usually taken by agriculture, ...
3
Because the first few decades are crucial, so we are pragmatically buying time until we manage the transition from fossil fuels to clean energy sources.
I heard a podcast announcing Ted's initiative called Countdown, where they presented planting a trillion trees as a solution. A company Flash Forest is being founded on Kickstarter to the amount of 100k to ...
1
If you consider what climate is -- the typical range of temperatures, precipitation, and other meteorological conditions that a region experiences -- and the fact that both nature and human society and civilization have adapted to the regional climates across the globe, then you can see that any substantial and relatively rapid change is likely to have what ...
0
Well the most straight forward way to radiate sunlight into space is with a mirror.
But creating millions of square miles worth of mirrors sounds very expensive. Probably in the range of a 100s of Trillions of US dollars. If we got rid of all government spending we might be able to pay for it over the course of a 100 years or so.
1
The problem with turning many forms of waste heat into other forms of energy by conventional (heat engine) methods is that significant temperature differences are needed - and that the temperatures making up the differences are counted from absolute zero (0 Kelvin). Only if that ratio is large, you get an efficient conversion. For example, if you look at the ...
4
Just to hammer it down: the amount of energy transferred to Earth by the sun every single day is colossal. In comparison, the heat generated by all human activities is negligible.
For instance, burning every single tree on Earth would release less than 1% of the heat the sun sends our way every day!
Taking human activities as an intuitive reference point is ...
1
Your idea: concentrating the heat, using the energy for something useful and then dissipating it into space could actually be accomplished by a space mirror.
There is a special orbit called L1 that's in between the Earth and the Sun and is just the right distance so that something in that orbit will track and orbit in sync with the Earth. It could both ...
1
Fossil fuel based energy is very inefficient; the amount of heat wasted exceeds that which gets used. In addition global heating from enhanced greenhouse effect is adding heat at rates estimated at around 100 times that from total waste heat. In order to get zero global heating (whilst continuing to burn fossil fuels) by collecting heat and sending it to ...
1
Of all the types of energy there is, heat is the "waste" of the energies. See, energy is only useful if organized, and heat is the least organized of them all. I.e, the energy must be able to push car wheel in that particular direction, not to every direction at random, like molecules of a hot gas would.
In order to reorganize the energy, according to the ...
2
Maybe this question belongs also into the space department here.
The only Lagrange point that makes sense is Earth - Sun - L1, and it is unstable (needs continuous correction). Satellites have already been put there, e.g. SOHO. But what we really need to do is cut down greenhouse gas emissions, anything else is not sustainable, or not practicable (a 300km ...
0
It would have to be a hell of a big disc, and in a geostationary orbit. No, it's not practical, we can never control the weather with satellites in space. It's a non-starter. What might be done with satellites is to reflect the sun's rays into frostbound valleys where there is a small town in shadow which is not getting the benefits of spring as early as ...
0
Much has been said about the negative effects, but there are positive effects as well. In UK thousands of old folk are speeded on their way to the promised land by hard winters, so milder winters will save thousands of lives. Excessively hot summers can also cost lives, but in UK those killed by cold weather greatly outnumber those killed by heat waves. ...
5
As others have pointed out, if you use the energy, it turns right back into heat.
Radiating it back to space is at least theoretically possible. But there is a problem with scale.
The Earth receives about a 100 petawatts of energy from the sun. And it radiates almost exactly the same amount back out.
Everything humanity do with energy is about 0.02 ...
27
Collecting thermal energy is really hard. As others have said, things like heat pumps exist for moving heat around, but the laws of thermodynamics (which are fairly fundemantal in physics) require that moving heat around will always generate more heat.
Now, the amount of extra heat generated can be less than the amount of heat that's being moved - so if we ...
11
Like passive radiative cooling?
The new materials reflect a broad spectrum of light, in much the same way as mirrors or white paint do. In the crucial 8–13-µm part of the infrared spectrum, however, they strongly absorb and then emit radiation. When the materials point at the sky, the infrared rays can pass straight through the atmosphere and into space. ...
50
Your middle school physics perhaps hasn't gotten to thermodynamics yet. The three laws of which can be summarized as 1) You can't win; 2) You can't even break even; 3) You can't leave the game.
The crucial point here is that heat engines don't actually work on heat, they work on temperature differences. So you can't really "collect" heat and turn it into ...
-5
Yes, it could reduce sea level rise, but it would be no good for irrigation. Many deserts, like the Aral Sea and Death Valley, are below sea level. This means you would not need to use energy to pump the water, but could use the siphon principle. Some people say that even if you filled all these low-lying deserts with sea water, it would not do much to lower ...
-3
Mankind does collect natural sources of heat and turn it into useful energy: heat pumps, solar arrays, geothermal etc, but it would be impossible to reduce global warming in this way. Most of the heat collected for useful purposes is in any case given back to the atmosphere when the energy is used. If you think about it, even wind farms are collecting solar ...
2
This is no an answer per se, just a back-of-the-envelope calculation for fun.
Lifting 1 kg (one litre) of water up a height of 1 meter uses 9.8 (let's say 10) joules of energy.
Let's say you want to lower the sea level by 1 meter. You need to pump 3.6e17 litres (3.6e14 m2 of ocean area = 3.6e14 m3 to pump * 1000 for litre conversion).
Let's say you want ...
2
I don't think there are any effects of climate change, which can be said to be particularly positive.
The level of CO2 in the atmosphere we're currently experiencing has not been seen on earth for about 800,000 years IPCC AR5 and the consequences of this change in radiative forcing are massive. Particularly as we've engineered this change in the last 150 ...
1
tl,dr: The direct effect of burning most of the fossil fuels (6 to 10°C temperature rise) may be survivable for some. But that does not take into account secondary effects triggered by the warming, like heat waves, ocean deoxygenation, flooding, melting of ice caps, etc.
The study below is already a bit dated, latest research has shown that earlier ...
1
Although conventional oil, gas and
coal reserves total between 829 and 1,501 GtC, estimates of the global recoverable fossil fuel resource including oil shales range upwards from about 4,000
GtC. If exotic resources, especially methane hydrates, are included the total
may be 15,000-25,000.
Millenial timescale carbon cycle and climate change in an ...
3
The short answer is that using atmospheric nitrogen as a feedstock for industrial processes doesn't really affect the climate per se. It does mess with the environment (primarily through deposition of nitrogen fertiliser) but this is a separate issue.
The problem from a climate point of view, is that the process is virtually certain to emit a lot of ...
0
So, there's really two questions here.
1) if we were to take wood and store it in a way that prevents decomposition, would this help reduce atmospheric CO2? and
2) Would sinking it into the bottom of an ocean trench achieve this?
So, first things first, yes removing wood from the contemporary carbon cycle does reduce atmospheric CO2. We already do this (...
5
Well, the amount and intensity of wild fires are a direct outcome of global warming, that's not really news.
According to this article that cites a work i can't find, until the mid of December 2019 the Australian fires emitted ~250million tons of carbon, ~50% of Australia's yearly production. A recovery in the coming decades is unlikely, because the ...
-2
It is unlikely that the Australian fires will produce enough particulates by themselves to induce measurable global dimming, but we can't be sure because the fires are not yet finished and could continue for months. Another thing to remember is that Australia is not the only country to have major wildfires, so it seems probable that the combined effects of ...
1
Very unlikely, especially as the major industrial nations will come nowhere near to meeting their greenhouse gases emission targets. Major volcanic eruptions, like major earthquakes, are random and unpredictable. The last really big volcanic eruption we had was Tambora, on the Indonesian island of Sumbawa in 1815. That caused climate cooling for a few years, ...
3
I found a decent review article by Zhang et al. (2015) covering various geo-engineering proposals that is worth reading. As for atmospheric pollution, they report that pollution should be injected at controlled altitudes into the stratosphere, where it is longer-lived. Using $\text{SO}_2$, apparently around $2-7 \text{Tg}$ of stratospheric injection would be ...
0
How much? A lot more than you could afford, and probably more than the government could afford. The most effective climate dimming agent is said to be sulphur dioxide,sprayed into the upper atmosphere, where it reflects the sun's rays back into space. Smoke and dust particles also have a dimming effect if there is enough of them. We get both of these effects ...
3
OilPrice
Petrochemicals are used to make numerous products.
Source
0
Here is the information that has the tool that you can do this
https://cds.nccs.nasa.gov/nex-gddp/
I have never use this but ran google it and found this..
0
You can use the formula ΔT=λ·α·㏑(C/C₀), (natural logarithm) where C is the later concentration of CO₂ and C₀ the earlier concentration. λ and α is constants. This formula is valid for a solid sphere but since 70 % of the surface of Earth is water, which warms up much deeper and accumulate about 90 % of the accumulated energy, it isn't totally clear how to ...
0
At present, only 51% of energy is reaching the earth surface (including oceans) in any given normal year with cloud cover as normal (excluding a peak sunspot cycle year which would have significantly reduced cloud cover across the earth). All of that energy makes its way out eventually as per a heat budget balance and so with reduced CO2 emissions of 410 ...
1
Heat does not accumulate on Earth. The Earth reaches an equilibrium temperature where outgoing thermal radiation balances incoming solar radiation, plus some smaller sources, of which our current energy production is a small part.
The geothermal heat flux from the Earth's interior is estimated to be 47 terawatts ... 0.087 watt/square metre, which ...
10
This also means a that greater amount of light goes back towards outer
space which is then absorbed by the greenhouse gases present in the
atmosphere.
No, it depends on the wavelength. Just like our body is transparent to X-Rays but doesn't let visible light through, greenhouse gases let sunlight through but absorb infrared light radiated by Earth.
...
0
No, it is low albedo which contributes to global warming because ground with low albedo absorbs more of the sun's rays. High albedo reflects them back into space, and therefore has a cooling effect. When the polar caps increase in size, this can lead to an ice age if the caps reflect enough heat into space. There can be a feedback effect whereby the more the ...
-1
The great hope for a carbon neutral future is, as you suggest, fusion power stations. Scientists are making good progress in this direction, but a commercial reactor is still two or three decades away. We won't have to limit the number of reactors because their production of dangerous wastes is negligible compared to fission reactors. The heat they will ...
23
This phenomenon is known as global dimming.
It was due to the particles and aerosols mostly released by combustion of fossil fuels such as diesel. Those particles block the radiation from the sun, so they have a cooling effect. For some decades this effect counterbalanced the warming effect of greenhouse gases, although it is no longer the case at a global ...
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