»The earth« is (or was) an self-stabilizing, adaptive system (see also Gaia hypthesis) More insolation leads to more evaporation of ocean water, more clouds, more rain – and the overall system cools down. However, outside certain boundaries, the earth-system is not self correcting and becomes unstable. For all we know (not »believe«) today, the earth system will become unstable with unthinkable consequences, if the current overall temperature increases by more than 2 °C.
Carbon Dioxide
There are a number of identified (and some unknown) causes why the climate is changing, CO2 and other greenhouse gases are the most-likely culprits. Carbon dioxide, CO2, from combustion of fossil material is only one of many factors driving warming. In geological history, the CO2 concentration has been much higher (up to 5% and more). So was the oxygen level over 30% in Late Cretaceous (which also led to different ozone concentrations). CO2 in the atmosphere goes up and down (think of all the carbonate rocks, which captured CO2 when they formed) – but it is one of the few parameters which we can influence. Others are the release of methane, PFC, etc. into the atmosphere.
What drives warming and cooling of the earth is the albedo, which in turn is primarily a function of clouds and ice-covered surfaces and, to a lesser degree, plant coverage.
In the Precambrian, when there was no life on earth and the atmosphere consisted of ammonia and methane, the climate flipped back and forth repeatedly between global glaciation and overheating. Later, the modern atmosphere, now with water-clouds and oxygen, which was generated by algae and the first plants that conquered the land in the Late Ordovician (and promptly caused a climate crisis and mass extinction event). With a few exceptions, this atmosphere has served us quite well as a climate-regulating buffer. When it did not work (e.g. end Permian, K/T-boundary, etc.) major taxonomic groups became extinct. Now, in our times, temperature is rising again and we observe the beginning of another mass extinction event.
If we take the past as a key to the future, we should think of all the extinct groups and not of the few that have survived. If mankind want to survive, we better do something about it.
Points to watch:
- The permafrost areas (Canada, Siberia). As the permafrost is melting, more methane, a potent greenhouse gas is released, the albedo reduced – and the planet is warming up even more (negative feedback).
- As the Greenland ice is melting, the northern Atlantic is filling with a layer of cold, low-salinity water.The low salinity keeps the melt-water on top of the denser marine water. The cool water layer is superimposed over the warm Gulf-Stream waters. The effect is less evaporation and therefore less rain in (western) Europe and less clouds and less precipitation over Greenland, which makes the ice melt even faster. Again negative feedback.
- A similar process may be going on in the NE Pacific and cause the increasing drought in the western USA (I have not yet all the details together).
- As the planet and the oceans are warming up, i.e. there is more energy in the system and therefore hurricanes are occurring more frequently with two very different consequences:
- Population leaving devastated areas and migrate elsewhere and
- the destruction of arable land, loss of topsoil (watch Brazil), less plant coverage (and, again, less clouds and even more warming).
Population and Migration
- Most of the population forecasts are flawed because they take only the age distribution of the population and the reproductive rate per age group as input. This is too simplistic because such an approach considers countries as separate containers with no migration, neither in nor out. Moreover, many simulations over-emphasize the contribution of India and China which constitute a major percentage of the world population and provide well-founded census data. But these countries are reaching their growth limits now or in a few decades. The conceptual mistake in these forecasts is not to take into account international migration – but the migration it has already begun. In the Americas, we see people moving to the north. Also in Africa, migrants are leaving their resource-poor home areas and try to make their way to Europe. No method whatsoever, no regulation and no fence will ever stop poverty migration. Some countries, such as the resource-poor and population-rich Egypt are still held together by external aid and money from the sales of oil and gas (as in the case of Nigeria, too), but not for much longer. The basic principle is that migration follows the main resources, water and arable land. Other resources, energy, commercial goods, are easily transportable. Thereby it is not relevant if the total world resources are sufficient to carry the total population. What matters is the change of resources and population in a given area. However, in most political systems and the leaders and »elite« are not capable (and not willing?) to deal with the changes.
- The fat cats of the world are already moving to places, where they hope, the crisis will hit a bit later, maybe Switzerland or a tropical island.
Summary
We can summarize that the overall interaction of water, air, clouds, temperature, and so forth is complex but it is also well researched and since the advent of super-computing power modeled with reasonable confidence.
- We know the earth is warming.
- The causes are most likely greenhouse gases.
- The world’s leadership(??) and elite is not prepared/capable/willing to deal with climate change.
- We are beyond the point of return. The do-nothing-case will inevitably lead to disaster.
- Negating the fact and the consequences is a waste of precious time – whereas, if earth warming would indeed not happen, the countermeasures taken would still be beneficial for our planet and all the life on it.