# Tag Info

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 ...

41

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 ...

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 ...

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 ...

23

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 ...

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. ...

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. ...

6

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

3

OilPrice Petrochemicals are used to make numerous products. Source

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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, ...

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 ...

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