How the climate is changing, what to expect and why March was warmer than April. Also, what is the role of methane emissions… Climatologist Nikolay Petkov spoke to FACTI.
- Mr. Petkov, why did March feel like April in Bulgaria?
- The reason it was so warm in our country, especially in the middle of the month, when temperatures reached summer values, was the prevailing southern transfer of warm air over our country, including Saharan sand.
The temperature deviations from the norm for March are from 1.7 °C to 4.7 °C, according to the National Institute of Meteorology and Hydrology. Taking into account the fact that this norm is based on the period 1991-2020, which is already significantly warmer than the previous 30 years, we can safely say that in a large part of Bulgaria the month had April temperatures.
For Sofia in particular, if we look at the available archives, we will see that this is one of the warmest months in meteorological observations in general, which began in 1887.
- What made March the second warmest in the world and with a global average temperature of 14.06 °C, which is 0.65 °C above the norm for the period 1991-2020?
- In general, the reason is the ongoing warming trend of recent decades. According to almost all scientists and leading organizations, this warming is caused primarily by the increase in the concentration of greenhouse gases in the atmosphere as a result of the burning of fossil fuels.
The last 2 years have been particularly warm, partly due to the El Niño phenomenon, when the surface temperature of the water in the equatorial Pacific Ocean is higher than usual, which temporarily warmed the entire world. In recent months, we have been in the opposite phase - La Niña, when the water temperature becomes lower than usual, most likely due to which we avoided a new record.
- And now we saw heavy snowfalls in April?
- Wet snow in April for 1-2 days, especially in the highlands, is not unusual for our country, it happens every few years. More worrying were the negative minimum temperatures, which destroyed a large part of the fruit plants, since they had already begun their development during the rather warm March.
In general, the dynamics of the weather are increasing due to climate change due to more energy in the atmosphere. Although the main trend is warming, some scientists believe that there is a paradoxical increase or at least a slower decrease in frosts in some regions of the Northern Hemisphere, primarily in North America. For Bulgaria, the main trend is that of warming - with an increase in hot and a decrease in cold events.
- Almost every subsequent year turns out to be warmer than the previous one. How long will this last?
- Barring a cataclysm like a large asteroid impact or a major volcanic eruption, this will continue until humanity stops emitting emissions or manages to compensate for emissions with massive carbon capture from the air - something that is almost never happening at this stage, as technologies are not yet sufficiently developed. Currently, only 0.1% of emissions are captured annually.
We will also have non-record years, but they will most often be among the warmest, in second or third place, for example. And if we look back just 5 or 10 years, the “cold” it will be record hot again right now.
- Is the Earth starting to “boil“, after the last 12 months were a full 0.71°C warmer than usual…
- Global warming is what journalists from “The Guardian“ call it, trying to emphasize the seriousness of the processes.
According to the latest assessment report of the Intergovernmental Panel on Climate Change (IPCC), the concentration of carbon dioxide in the atmosphere in recent decades has been the highest in 3 million years, when the Earth's temperature was about 3 degrees higher than the present.
- The series of record or near-record high temperatures for the entire globe has been going on for almost 2 years. How long will it last?
- It is unclear. It is likely that we have crossed a new long-term threshold and will hardly see a decline back in the coming decades. We see that warming often has periods of more stable temperature and its slow increase, such as the period 1998-2012, followed by years of sharp warming. We are currently in a new period of warming.
- When will the Earth start to cool…
- After stabilizing the concentration of greenhouse gases in the atmosphere, warming will stop in a few decades, but it will take millennia for the temperature to drop to that of the late 19th century.
The case of methane is interesting - the second most important greenhouse gas, since its warming effect is 28 times stronger than that of carbon dioxide. However, it has a much shorter residence time in the atmosphere, so if we immediately stop all methane emissions, cooling of about 0.5 °C will follow over the next 100 years, or at least warming will slow down by the same amount if emissions from other gases continue.
- What happens to seawater when it gets warmer outside?
- Seawater also warms, although more slowly than land, because water can absorb more heat. But sea surface temperatures are also already at record highs in much of the world. According to the Copernicus report on the state of the climate in Europe in 2024, they were at record highs in the Mediterranean Sea and most of the Black Sea.
- The ice is melting. When will we see grass in the Arctic?
- According to the IPCC, there is a high probability that the Arctic will be ice-free by 2040. Although since 2012 no new absolute ice minimum has been recorded (such a thing may occur in September during the annual minimum of ice volume at the end of the polar day), record low areas continue to be recorded for other months of the year and now we have a record low ice maximum for March.
- It seems that the global temperature will remain above the 1.5 °C threshold for this year as well, because…
This year is most likely cooler than last year due to the end of the El Niño phenomenon. Scientists expect it to be the third warmest, which is why 2025 is possible to remain below the 1.5 °C threshold. Here it also depends on the analyses of which scientific organization we are considering, since each one calculates the global temperature differently. For example, according to NASA, the temperature may remain at the 1.5 °C threshold, but according to the “Copernicus“ agency to be above it.
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Nikolai Petkov graduated from the Master's degree in "Meteorology" at the Faculty of Physics of the Sofia University "St. Kliment Ohridski". His Master's thesis is on the topic of "Climate indices - analysis of the climate over Southeast Europe in the recent past and present". He works in the environmental association "For the Earth" as an expert and coordinator. He is currently pursuing a Master's degree in "Integrated Climate System Sciences" at the University of Hamburg in Germany, author in Klimateka.