He calculated the amount of moisture and radiation in and out of the atmosphere at all latitudes of the earth and declared that doubling the amount of carbon dioxide in the air would raise the Earth's temperature by about 5 ° C,

which he later adjusted to 4 ° C. Later, people were surprised to find that without the support of modern supercomputers, the results of his research fell well within the temperature increase estimated by scientists in recent years, which was a genius analysis.

In 1896, the carbon dioxide released by burning coal only raised carbon dioxide levels by one-thousandth of a percent. According to Arrhenius' calculations, it would take thousands of years to double the amount of carbon dioxide in the air. Of course, he did not expect that the process of industrialization would develop so quickly.

Callender first proposed global warming

By the 1930s, the climate had entered a warm period. Many old people say that the weather is really not like before. The terrifying snowstorms of their childhood memories, the frozen lakes of early fall, it was all over. The younger generation caught the good weather. The mass media began to flood with articles proclaiming that winter really was getting milder.

Meteorologists scrutinizing their own records confirm the story: a warming trend is on the way. Experts told Science reporter: "The frost is late, and the north, where wheat and crocodiles have not been seen for centuries, can now harvest wheat and catch crocodiles."

Meteorologists explain that there are always modest changes in weather patterns, which can last for decades or centuries. One man, however, came forward with a "striking statement" - Guy Stuart Callender, who spoke about climate at the Royal Meteorological Society in London in 1938.

Callender seems to be overstepping his role, since he is not a professional meteorologist or even a scientist. He was only a steam power engineer, and climate was his hobby, and he devoted much of his spare time to compiling meteorological statistics.

"The data do show that many places on Earth are warming," he said. Now Callender tells the meteorologists that he knows who is to blame for warming - us, human industry! We burn fossil fuels everywhere, emitting millions of tons of carbon dioxide, which is changing the climate.

The amount of carbon dioxide in the atmosphere has risen a little since the early 19th century, Callender said. Experts are skeptical. They knew that no one could make reliable observations of trace amounts of carbon dioxide in the atmosphere. Callender seems to be just cherry-picking the data to support his point of view!

Callender is the first to claim that global temperatures have risen, and that this warming is due to the increase in carbon dioxide emissions since the Industrial Revolution. However, Callender believes that the situation is not urgent,

and the warming climate is even good for humanity - it will help crops grow more abundant. He calculates that we will increase the global average temperature slowly - perhaps by 1 ° C by the end of the 22nd century.

Carbon dioxide is really increasing!

When Charles David Keeling was a postdoctoral student at Caltech in the mid-1950s, he had a burning desire to actually measure whether the concentration of carbon dioxide on Earth was really changing.

Keeling is not the first to think this way. A group in Scandinavia has tried a monitoring program. Their measurements of carbon dioxide fluctuate wildly from place to place, and even from day to day, as passing air masses carry the gas emitted by forests or factories in pulses. "It looks hopeless to use this measurement to reliably estimate the atmospheric CO2 pool and its long-term changes," admits one expert.

But Keeling didn't believe it. He did it himself, spending months of research and labor to make the instrument. Patiently refine your technique by taking measurements at several locations around California.

Keeling lobbied key officials and finally persuaded them to provide the required funds. He set up two observatories, one on the top of the Mauna Loa volcano in the Hawaiian Islands, surrounded by thousands of miles of clear ocean, one of the best places to take measurements of Earth's undisturbed atmosphere. Another instrument was placed in an even more pristine part of Antarctica.

Keeling had expensive instruments and pursued every possible source of error. At the South Pole, he traced measurements of carbon dioxide that were influenced by emissions from nearby machines;

At Mauna Loa, he found that gases erupting from the volcano itself were interfering. After careful tracking of similar questions, Keeling has produced an unusually precise and stable baseline of carbon dioxide levels in the atmosphere. The first 12 months of data he collected showed that the concentration of carbon dioxide had risen within a single year.

In 1960, with two full years of Antarctic data in hand, Keeling reported that the baseline carbon dioxide levels had risen.

As Mauna Loa's data accumulated, the records grew more impressive. It shows that carbon dioxide levels are rising significantly from year to year. What Keeling initially saw as a temporary job has turned into a lifelong career.

Within a few years, Keeling's unshakable carbon dioxide curve was widely cited by scientific review panels and science journalists as a central symbol of the greenhouse effect.