Humans are probably responsible for climate warming, and are definitely contributing to it. But now things may be out of our control!
These days, almost everybody agrees that the climate is warming. If you do not agree, look at the two graphs below and you will change your mind.
However, there is still disagreement as to whether human emitted greenhouse gases are causing climate change. If human emitted greenhouse gases are not causing climate warming, why should governments spend a fortune subsidizing new energy sources?
In my opinion, recent climate warming was initiated by human caused greenhouse gases. Any alternative theory must explain why temperatures stayed within a less than one degree C range for eight thousand years, but has been rising rapidly (and steadily, if you take pollution into account) since mid-19th century industrialization — by 1.8º C (3.2º F) as of this writing. If there is a non-human cause, it is a strange coincidence! But, yes, coincidences do occur. Regardless of whether initially it was due to humans, greenhouse gases are now the main cause of climate warming.
Having studied every non-greenhouse-gas alternative cause that I know of, I cannot find one that holds up scientifically. You will find this discussed in the scientific sections of this website, including changes in the earth’s orbit, location in the galaxy, the sun radiation, ocean currents, undersea magma, land use, and volcanos.
Additionally, satellites confirm that greenhouse gases are increasingly insulating the earth. For one thing, the atmosphere above the greenhouse insulating layer is becoming colder — that is, less heat is passing through the greenhouse layer. For another, less heat is escaping from our planet than is being received from the sun.
In my opinion, the above arguments are definitive; There’s no need to consider anything else. However, let us look at the counter arguments.
First, some have claimed that the Covid lockdown proved that humans are not contributing to climate change. However, human CO2 emissions are only about 8 % of plant and microbial emissions1 which vary more than this from year to year. While human emissions add to the average yearly increases in CO2 emissions, natural causes are almost entirely responsible for the yearly fluctuations. A 7% reduction of human emissions during COVID is far too tiny to be detected against the base of natural fluctuations. Yearly CO2 additions to the atmosphere are increasing in line with increased fossil fuel use.
Second, those who say humans have not a cause of climate warming also argue that climate temperatures have fluctuated in the last 8,000 years more than recently. Those who make this argument pick on data from one (or another) location of the earth, or measurement method. The first graph below shows that when the different locations are averaged together, there has been very little temperature change. Furthermore, no measurement method in the last 12,000 years shows and increase as high as we have now, and none for the last 2,000 years before 1900 shows an increase of more than 0.4 degrees C.
Third, opponents of CO2 as a cause of climate warming argue that data of the last 500 million years proves that CO2 is not a cause, that CO2 doesn’t correlate with temperature, or that CO2 has followed temperature changes. Proponents of CO2 as the cause of climate warming use the same data to argue that CO2 caused it!!! In my opinion, since, we do not know all the conditions of the past 500 million years, we should ignore these pro and con arguments . We do know what is measured today.
Fourth, opponents of CO2 argue that CO2 levels since 1852 have not correlated with fluctuating temperatures. This is true if you do not adjust the data for changes in air pollution, which has a big effect. Once you adjust the data, they correlate.
Below are two graphs2 3showing how temperatures held steady for thousands of year, but have shot up by 1.1 C to 2016, and another 0.8º C as of this writing. The colored line on the first chart are using different locations and methods. Today’s temperature higher than any maximum of any line on the first chart.
As of this writing, despite all the publicity and efforts, on balance worldwide humans are helping accelerate climate warming and are not slowing it. I discuss this here: Are we slowing climate warming?
And now, greenhouse gases are not the only reasons for climate warming. The causes of climate warming.
