February 2024 had the highest sea temperatures ever measured by Copernicus, the climate monitoring service of the EU and the European Space Program (ESA). This is just the latest record in an ongoing undersea heat wave, which has hit all the world’s oceans. – We are seeing an extreme situation, says Tore Furevik, director of the Nansen Centre. Especially the temperatures in the Atlantic Ocean have shocked several climate scientists. – The North Atlantic has almost had 12 months in a row where all the days have set a new record. All the days have been far warmer than earlier in the same season, says Furevik. The Great Barrier Reef in Australia is again affected by hot seas. For the fifth year in a row, the coral reef has been affected by so-called mass bleaching following high temperatures in the seawater, the Australian authorities said on Friday. Australia’s iconic Great Barrier Reef. Photo: Sam McNeil / AP Pollution theory Scientists have expected heat records, since we are in a period of the naturally warming El Niño weather system. That is to say, El Niño comes on top of the warming from humanity’s enormous greenhouse gas emissions. – That there will be new records is not surprising. But that the records should be so high or so strong is surprising, explains Furevik. Again, the North Atlantic is particularly surprising. Because this is an ocean area that should not be affected by El Niño’s extra heating. One explanation that is being speculated about is that there has been less pollution in the area, due to new rules for ship traffic. Simply explained, particles in pollution have previously contributed to forming clouds that have blocked more of the sun’s rays. CO₂ in the atmosphere measured in parts per million particles (ppm)460 parts per million particles (ppm)? Click for an explanation of parts per million, abbreviated ppmGo to news’s Climate Status Why is the graph so wavy? This is about seasons. In summer, the amount of CO₂ decreases because plants and trees absorb CO₂ from the air. In winter, the plants die, the CO₂ escapes and the graph rises. Since there are more plants and trees in the northern hemisphere, the seasons here control the amount of CO₂ in the atmosphere. What is the problem with a lot of CO₂ in the atmosphere? The greenhouse effect makes the earth livable, but more greenhouse gases, such as CO₂, increase this effect and make the earth warmer . The graph starts in 1960 because this was the year when the world began to measure CO₂ systematically. It happened on Mauna Loa in Hawaii and the curve shows the measurements from there. Before the world became industrialized there was around 280 ppm CO₂ in the atmosphere (year 1700). The researchers found that out by analyzing ice core samples. Will there be less CO₂ in the atmosphere if emissions are cut? No, not immediately. If we cut emissions, the amount of CO₂ in the atmosphere will only increase more slowly. The reduction in emissions must be large and last for a long time before we can see an effect. Imagine that the atmosphere is a bathtub and the greenhouse gases are the water you fill in. Even if you turn off the tap, the bathtub will not run out of water. This is the case with greenhouse gases and CO₂. It takes a long time for CO₂ to break down in the atmosphere. This is the reason why the experts want technology that sucks out greenhouse gases from the atmosphere, in addition to us cutting emissions. The world’s politicians have decided that they will try to limit the warming of the world to 1.5 degrees, compared to how the temperature was before the industrial revolution. Then we must keep the amount of CO₂ in the atmosphere below 430 ppm, according to the UN’s climate panel. – So you can say that parts of the man-made warming have been dampened or masked by pollution, Furevik explains about this theory. That’s why warm seas are a problem An ongoing heat wave in the ocean affects the world in several ways. – One thing is that all weather in the atmosphere is largely controlled by the surface temperature of the sea, to put it very simply, explains Furevik. So extra warm oceans can affect extreme rainfall, droughts, heat waves and wildfires. A home in ruins after the largest wildfire ever in Texas, which has raged in recent weeks. Climate scientists say the forest fire season is getting longer because of climate change. Photo: Nathan Frandino / Reuters Another thing is how it affects marine life. Coral reefs, for example, are very vulnerable to high sea temperatures. The beautiful and colorful ecosystems teeming with life can be bleached and destroyed. And the world is facing the fourth mass bleaching of coral reefs, including in parts of Australia’s iconic Great Barrier Reef, according to the US National Oceanic and Atmospheric Administration (NOAA). – We are on the verge of the worst coral bleaching in the history of the planet, says Derek Manzello at NOAA to Reuters. Australia’s iconic Great Barrier Reef. Photo: AP Nine months of records At the same time, we have just put behind us the warmest February ever measured on land, according to the EU’s climate program Copernicus. It will be the ninth month in a row with record heat. Temperature in the world since 1880 compared to the average in the period 1991-2020 +0.5°C compared to normal? Click for explanation normal temperature 18801900192019401960198020002020Go to news’s Climate Status Why are most years blue and colder than normal? This is because all years are now compared with a new normal, i.e. the average weather in the 30-year period 1991-2020. These 30 years have been unusually warm. Most other years are therefore colder than normal. Until recently, researchers used a normal period that ran from 1961-1990. In these years it was relatively cold. It’s been quite a while since the 1960s and the new normal allows us to compare the weather with the climate (normal) that people actually experience today. The normal period is determined by the World Meteorological Organization (WMO), and is used in all countries . In this way, we can compare the weather in Norway with other countries and we can measure changes across the globe. How can you calculate one temperature for the whole world? This number is the result of a complicated calculation. Measurements are made with thermometers both on land and on the sea surface (at sea the thermometers are attached to buoys). In some places the thermometers are close together, in other places they are far apart. Using a statistical method, the researchers are able to give the measurements different weights, so that all areas are equally important: The data used in this graph comes from the American NOAA. They have divided the globe into squares of 5° x 5° and calculate one temperature for each square. Then they can again work their way up to a global figure, for each month or for each year. They can also make figures for the temperature only over the ocean or only over land, or for the northern and southern hemispheres. The lines at the poles are smaller than along the equator due to the curvature of the globe. The researchers also take this into account in their calculations. Others, such as NASA or the Hadley Centre, calculate in slightly different ways than NOAA. Therefore, there are often small differences between the various data sets. In any case, the trend they show is the same: since 1880, the world has become warmer. And it is human emissions that have been responsible for the majority of the extreme heat, states the World Meteorological Organization (WMO). This despite the fact that El Niño was one of the strongest ever measured. El Niño will soon be replaced by the cooling weather phenomenon La Niña. Therefore, this summer will probably not beat last year’s many records. But the world is approaching a point where not even La Niña’s cooling effect will be able to compensate enough for the emissions to keep the heat records in check, says Furevik. He is crystal clear on what is needed to stop the extremes: – Emissions must be reduced to zero in order for us to be able to stop growth. If we are to bring the temperatures back down, we actually have to start getting CO₂ out of the atmosphere again. And it is a challenge in every way. The ski season did not go as planned in several places in Europe this year.
ttn-69
– Extreme situation – news Norway – Overview of news from different parts of the country
