Apart from a few snowflakes today (Wednesday) and a not too spectacular cold front at the weekend, sunshine and mild temperatures are here to stay. On the occasion of the climate conference in Paris and because the weather outlook isn't particularly exciting, we're reiterating a few basics today.
After today's disturbance has passed, it will be sunny and warm again on Thursday and Friday. On Saturday, a weak front will bring some precipitation in the north, but it won't be really heavy. The main ridge and the areas south of it should remain largely dry. Basically, the familiar mixture of high pressure and mild westerly influence is likely to continue for a while. A sustained changeover to colder temperatures is only indicated in the so-called UGKB (ultra-globular range, meteorological term) and is by no means fixed.
What is the greenhouse effect?
If our atmosphere contained no greenhouse gases, we would have an average temperature of -18°C on Earth. You might think that this would at least be better than the current weather, but it wouldn't be really survivable for the human species (skiers included) in the long term. Fortunately, however, our atmosphere contains various gases that keep the earth at a reasonably pleasant temperature. Solar radiation can penetrate the atmosphere relatively unhindered on its way to the earth's surface. Once it arrives, it heats the surface. This in turn emits radiation at a wavelength that is absorbed by the greenhouse gases in the atmosphere and partially reflected back. This makes it significantly warmer than it would otherwise be. The main greenhouse gases are water vapor, followed by CO2, methane and ozone.
What is the carbon cycle?
Life on Earth, including us, is based on carbon (we're still not carbon chauvinists, of course!) It's everywhere: in the atmosphere, the hydrosphere (water), the lithosphere (rocks and stuff) and the biosphere (plants, animals, skiers). Carbon is moved back and forth between all spheres in a fairly slow exchange. For example, CO2 from the atmosphere dissolves into rain, which falls on the ground. As the rain is slightly acidic due to the CO2, it dissolves certain substances from the soil, these are transported from the rivers into the sea and there they are processed by various creatures into something (corals, calcareous shells, etc.). This something eventually dies and sinks to the seabed, where it slowly turns back into rock.
When entire living organisms (organic carbon) die and slowly sink to the bottom, for example, enclosed in mud
, pressure and heat also cause rock to form. In certain cases, such material (=organic carbon) accumulates faster than it decomposes. In this case, no sedimentary rock is formed, but oil, coal or natural gas. Sooner or later, the exchange goes the other way again, for example through volcanic eruptions. The whole process takes a few hundred million years.
The exchange of carbon within the biosphere and between the biosphere and the atmosphere is much faster. Plants extract CO2 from the atmosphere and use it for photosynthesis. When the plants die, much of it ends up back in the atmosphere. The CO2 that we exhale comes from our food. It is therefore part of the 'fast' carbon cycle.
The situation is different when we burn fossil fuels. When we do this, we are interfering with the 'slow' cycle. Carbon that has been locked up in the lithosphere for millions of years suddenly becomes CO2 in the atmosphere in large quantities. A large proportion of this extra CO2 is nevertheless absorbed by plants and, above all, the oceans. However, a not insignificant proportion also remains in the atmosphere.
What's the problem?
More greenhouse gases in the atmosphere mean that the greenhouse effect is getting stronger. It gets warmer. The extra CO2 has various other effects. Plant growth is favored, but only as long as the other necessary ingredients are available (water, nutrients). The acidity of the oceans increases as more CO2 is absorbed. This has an impact on the corresponding ecosystems and tends to be bad for animals with calcareous shells, for example.
The more you turn the big system screws, such as the carbon cycle, the greater the impact on the system will be sooner or later. Environmental conditions to which we and the rest of the biosphere have adapted change and at some point you reach the point where you can no longer adapt quickly enough to the new conditions. Systems start to break down. These can be delicate ecosystems, such as on the Great Barrier Reef, or systems of human society, which in some parts of the world, for example, eventually cease to function due to a shortage of resources.
At what level of warming it becomes 'dangerous' is the subject of much debate and depends, among other things, on the definition of 'danger'. The 2°C guideline is now rather outdated and probably also rather unrealistic as a target.
Of course, you can imagine various horror scenarios of what lies ahead - fewer powder days are generally less of a problem. However, we can (should?) hope for a bit of social changeability and perhaps even common sense, at least according to the WeatherBlog. Investments in renewable energies are increasing, new technologies are becoming cheaper and more effective. In any case, it remains exciting.
We recommend this detailed and well-explained article from NASA to read more about the carbon cycle and potential changes to it.
