Satellites may have been underestimating global warming for the last 40 years, scientists warnÂ
Satellites have measured the Earth's atmosphere for decades, notably showing the impact is having on the planet. A new study suggests that the measurements from the man-made celestial objects may have underestimated the impacts of warming for the last 40 years. The research, looked at the basic properties of tropical climate change; when combined with the equations that show the correlation between temperature and moisture, the experts found there were significant disparities. 'It is currently difficult to determine which interpretation is more credible,' said the study's lead author, Lawrence Livermore National Laboratory climate scientist Ben Santer, in a . 'But our analysis reveals that several observational datasets particularly those with the smallest values of ocean surface warming and tropospheric warming appear to be at odds with other, independently measured complementary variables.' Essentially, the satellite measurements of the troposphere have either underestimated the temperature or severely overestimate the amount of moisture in the atmosphere. The researchers looked at four different properties of climate change: tropical temperature and tropical water vapor sea surface temperature to tropical water vapor, lower tropospheric temperature to tropical water vapor and mid- to upper tropospheric temperature to tropical water vapor. All of these ratios are 'tightly constrained' in climate simulations, essentially meaning that more heat is required for moist air than dry air because of the efficiency of water. In their findings, the researchers noted that the satellites had a 'systematic low bias,' falling within a range that was larger than what the ratios would otherwise dictate. 'Nevertheless, our analysis reveals anomalous covariance behavior in several observational data sets and illustrates the diagnostic power of simultaneously considering multiple complementary variables,' the researchers wrote in the study's abstract. At this point, the research showed that the data that followed the ratio between water vapor and temperature were most likely to be those that showed the most warming of the seas and troposphere. One of the study's co-authors, LLNL's Stephen Po-Chedley, said the comparisons could give new credibility to a wider range of data and become more precise with their findings. 'Such comparisons across complementary measurements can shed light on the credibility of different datasets,' Po-Chedley said in the statement. 'This work shows that careful intercomparison of different geophysical fields may help us determine historical changes in climate with greater precision.' The findings have been published in the . Levels of carbon dioxide, one of the greenhouse gases largely responsible for climate change, are rising, even when taking into account the impact of the COVID-19 pandemic. Carbon dioxide levels surged in 2020 to 2.6 parts per million, one of the highest recorded since NOAA started tracking more than 60 years ago. Since 2000, atmospheric CO2 has risen about 12 percent and atmospheric methane has increased six percent. In early January, NASA that 2020 was the warmest on record, tied with 2016. The global average temperature was 1.84 degrees Fahrenheit (1.02 degrees Celsius) warmer than the mean between 1951 and 1980.