Why global warming is not a myth and is it possible to “fix” the climate?

We often hear about climate issues, but we don't always know what information to trust about global warming. Climatologist Alexander Chernokulsky helped listeners of the Science Pulverizer podcast understand the most important issues.

Is it true that global warming can threaten humanity?

Humanity will survive - that's obvious. The question is in what quantity and quality.

Global warming is not a myth. If on a scale of millennia the climate is influenced primarily by astronomical and geological factors, then on a scale of 10–100 years the main cause of change is now the activity of man himself. That is, the temperature on the planet depends on our actions.

We burn fossil fuels and add additional molecules of carbon dioxide, methane, and nitrous oxide to the atmosphere. This increases the temperature of its lower layers. At an altitude of more than 80–90 kilometers, it, on the contrary, decreases, because we are increasing the greenhouse effect. Excess heat remains at the surface, and the largest part of it - about 90% - goes into the ocean.

Temperatures on the planet are rising in leaps and bounds. A sharp surge occurred in 1998, the next one in 2016. Now we are most likely seeing another surge. Global surface temperatures will exceed 17°C this year.

The Paris Climate Agreement says that everything must be done to keep the increase in average temperatures to within 1.5ºC. It was above that level for several months this year. It is obvious that we will exceed the 1.5 °C indicator. It may be possible to stop at 2°C, but most likely not.

If we look at the global impact of warming, we can see that it is affecting the planet negatively. More likely, humanity Serious changes await, but it will be able to adapt to them.

Is it true that due to warming, familiar foods may disappear or change taste?

Yes, there are products whose taste greatly depends on the climatic conditions in which they are produced, for example, wine and coffee. Perhaps, due to warming, they will be produced in new regions. And other tastes will appear, as well as a new price and other supply channels.

Familiar products may become more expensive, but they are unlikely to disappear completely. Although some crops may disappear - for example, those grown in the mountains. With warming, it will no longer be possible to move their plantations higher: there may not be suitable soil there. So local losses are possible.

But the main thing that can change is our eating habits. If humanity really understands that it is necessary to reduce CO₂ emissions, then perhaps by the end of the century people will eat more plant-based foods. And less meat, because its production significantly increases the carbon footprint and increases the greenhouse effect.

This trend is likely to grow, although not in all regions. Dietary changes can be a conscious choice to mitigate the effects global warming.

In general, if we talk about humanity’s response to climate problems, we can distinguish two main strategies. The first is adaptation, that is, the desire to adapt to inevitable changes. The second is mitigating these changes.

Will the number of natural disasters on the planet increase?

Natural disasters occurred in Earth Always. But today we are seeing two trends at once: an increase in our exposure to hazardous events and an increase in their intensity.

The first appeared when people stopped living compactly and populated almost the entire ocean coast. Therefore, they are now more susceptible to the effects of hurricanes and typhoons than before. The expensive infrastructure that has appeared on the coast is also suffering.

Regarding the second trend, there is scientific evidence that the number of storms, hurricanes and tornadoes changes very little. But they become much stronger and bring more disasters. In the seventies, the share of category 3–5 hurricanes and typhoons was about 30%. Today it is already 40%. That is, there is a 10% increase in powerful manifestations of the elements that lead to serious floods and destruction.

It is becoming more difficult to combat drought. If we talk about agriculture, the main problem may be the lack of water. This trend is especially noticeable in the subtropical zone. There, the weather is influenced by anticyclones, which become more intense and move closer to the poles. Therefore, in the Mediterranean region - for example, in Greece and Portugal - there will be more dry periods, and therefore more forest fires.

But sometimes completely different phenomena form over the Mediterranean Sea - hurricanes.

Similar phenomena may occur over the Black Sea. We have already seen such medicines in 2005 or more recently - in 2021.

We have already shown in scientific articles that the event in Krymsk in 2012 was caused by the warming of the Black Sea. Then the most powerful thing happened flood: 300 mm of precipitation fell in two days. A dam of branches was created under the bridge, which broke through at night, causing the water level in the river to rise sharply. A five-meter wave passed and more than 170 people died. If a similar cyclone had passed over the Black Sea in the seventies, such rains would not have happened. But now the water in it has become warmer, and now strong tropical downpours have appeared on the coast.

Such dangerous phenomena will occur more frequently in many regions of Russia. The south of Siberia, the middle zone, and the Far East are under threat - these are regions where dangerous convective phenomena will intensify. And these are not only heavy downpours, but also large hail, squalls, tornadoes, and tornadoes.

But there is also a positive effect of climate change. Severe frosts will weaken and winters will become milder. This process is already happening, and we see that excess cold mortality is decreasing in our country.

What can we expect from rising sea levels?

Yes, due to climate change, the level of global ocean rises. And this process is going much faster than in the past. In the 20th century, this level rose by about 2–3 cm per 10 years. Now the ice of Greenland and almost all mountain glaciers have begun to melt more actively - for example, in the Caucasus, in the Cordillera, and the Andes. Large masses of water are added to the ocean. And its level is growing by 4.5 cm per decade. Therefore, intensified tropical cyclones can flood areas that are deeper rather than near the coast.

Such natural disasters can really wipe out, if not countries, then individual cities. The greatest danger threatens the coasts of the east, southeast and south of Asia, cities on the coast of North America, as well as the islands of Oceania.

But humanity is trying to adapt to the elements. For example, from hurricanes mid-level can protect embankments. And the research of scientists and their forecasts of natural disasters will help save people’s lives from powerful hurricanes.

Why are winters getting colder in some regions?

An interesting point: while the southern countries are languishing from the anomalous heat, residents of the northern regions notice that winters are getting colder every year. And summer can also be very cool. However, this fact does not refute the conclusions about the development of global warming.

Winter temperatures on the planet are not falling - on the contrary, they are rising. This is easy to see if you compare current indicators in all regions with the same data in the past. The average winter temperature on Earth is increasing. But there are indeed regions where in recent years frosts have been as severe as before.

The weather in temperate latitudes is largely determined by westerly transport - the movement of air from west to east. For example, a moderate air mass comes to us from the Atlantic and creates a mild climate. The strength of this transfer depends on the pressure difference between the pole and the equator, and this difference is determined by the temperature difference.

But with warming, the pole heats up faster than the equator. Therefore, the difference between them decreases, and the western transfer weakens.

So a cold winter or cool summer does not at all prove that there is no global warming. If it is cold in one region, then somewhere in the neighborhood there is abnormal heat.

How can we really slow down global warming?

Several directions can be distinguished here.

Carbon geoengineering

We will not be able to completely reduce our carbon footprint to zero, so we should somehow compensate for emissions. For example, removing carbon from the envelope of the climate system. First of all, of course, from the atmosphere. But if we can clear excess carbon from the ocean, it will absorb CO₂ from the air.

Scientists offer many ways to remove excess carbon dioxide from the atmosphere or oceans. And then either bury the carbon or reuse it. To do this, you can try to influence chemical processes in the ocean. For example, add minerals that alkalize the ocean and remove CaCO₃.

In short, today carbon geoengineering is a very important and promising direction.

There are also fundamentally different proposals - for example, covering part of the Earth's surface with white paint so that it reflects the sun's rays. But this is a classic fight not with the disease itself, but with its symptoms. Such measures will in no way reduce the concentration of greenhouse gases in the atmosphere, and they are the main problem. Therefore, we need to reduce our carbon footprint first.

Reducing your carbon footprint

The main way to stop increasing greenhouse gases is to switch to renewable energy sources. This means gradually abandoning coal, and then other hydrocarbons. Switch to hydrogen fuel, increase the share of electric vehicles.

Well, each of us should gradually abandon the habits of consumer society. For example, stop changing smartphone Every year.

Of course, the carbon footprint of one person cannot be compared with that of an industry. Therefore, we should choose those products that are produced with lower CO₂ emissions. And manufacturers will receive a signal which products are in demand and which are not.

It is important that climate change does not have a single point of no return. We have already passed many such points, but others have not yet. So humanity has time to try to at least somehow slow down global warming and adapt to it.