I feel that the weather is getting hotter and hotter, no doubt about global warming. On the contrary, I sometimes come accross the researchers who are suspicious about global warming and its causes, and the number is increasing. Today I have checked some facts and give my opinion.

Daily high and low temperatures have been recorded at thousands of weather stations worldwide for many decades, and in some locations, for more than a century. When different teams of climate scientists average these data together, they all find essentially the same result: Earth’s average surface temperature has risen by about 1.8°F (1.0°C) since 1880. (1)

Even from the data, some scientists believe that 100 years of data is not enough to understand the general trend of temperature rise and fall. This is reasonable if we consider the Earth’s history: there have been eight cycles of ice ages and warm periods in the last 800,000 years, and the period is ~100,000 years.(2) 100 years in 100,000 years is a really small part of the period.

       Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that Earth’s climate responds to changes in greenhouse gas levels. Here are Greenland’s ice loss data for the last 20 years. (3) Ancient evidence can also be found in tree rings, ocean sediments, coral reefs, and layers of sedimentary rocks. This ancient, or paleoclimate, evidence reveals that current warming is occurring roughly 10 times faster than the average rate of ice-age-recovery warming. Again, the 20-year data is just a glimpse of the Earth’s history, and we cannot deny that this data really represents the general trend of the Earth.

        The most suspicious part of global warming is that it is caused by greenhouse gases, mainly carbon dioxide. Of course, there is a clear correlation between global temperature and the concentration of carbon dioxide. (1) However, the correlation does not prove the cause, it merely mentions the relationship. The sceptics believe in global warming, but do not believe that it is caused by carbon dioxide. The display of the graph is also intentional. The vertical axis of carbon dioxide concentration and global temperature is a small fraction of the original values, ~20 degC and ~300 ppm. This type of graph is probably only seen in environmental research.

        The other problem is that there is little data on the quantitative amount of energy stored in carbon dioxide. Carbon dioxide has an absorption around 4.3 and 15 microns in wavelength, methane is around 7-8 microns. (4) Many do not know the exact estimates of the increase in greenhouse gases and how much energy is actually being absorbed and stored in the Earth, and how much the temperature is raised. Whatever suspicious evidence there is about global warming, it is at least statistically true. In view of the vital results in the future, we researchers must take responsibility and take action. There are many proverbs in every country that say “it’s too late when something happens”, we have to take it as true and do something.

(1) https://www.climate.gov/news-features/climate-qa/what-evidence-exists-earth-warming-and-humans-are-main-cause
(2) https://climate.nasa.gov/evidence/
(3) https://www.climate.gov/news-features/featured-images/2019-arctic-report-card-melt-season-greenland-ice-sheet-rivals-record
(4) Wei, P, et al. Heliyon. 2018 Oct; 4(10): e00785