There a still some people who deny that the global warming we are experiencing is unnatural and that it is being caused by human activity. Here are three charts that prove that the deniers are wrong.
This chart shows that, since the beginning of the Industrial Revolution, our burning of fossil fuels has added almost 2 trillion metric tons of carbon dioxide to the atmosphere…
This next chart shows that, as a result of these carbon dioxide emissions, the atmospheric content of carbon dioxide has increased by 45%, rising from 286 parts per million to 415 parts per million…
Note that the concentration of carbon dioxide is extremely small – just a few hundred parts per million. This shows that it takes only a very small amount of carbon dioxide to warm the planet. If there were no carbon dioxide, the Earth would be frozen solid. This is why, even the relatively small amount of additional carbon dioxide humans have added can have such a significant effect on the global average temperature.
The third chart shows the global average surface temperature over the past 1700 years. Note that, after 1500 years of relative stability, temperatures began shoot up at the end of the 19th century. This rise corresponds exactly to the rise in human-caused carbon dioxide emissions and the resulting increase in the atmospheric concentration of carbon dioxide. The last time the planet was this warm was 130,000 years ago.
How does carbon dioxide warm the planet? The Earth is heated by the sunlight it receives. This solar radiation has a frequency that allows it to pass through carbon dioxide and penetrate to the Earth. The Earth then radiates heat back out to space in order to keep a stable temperature. This radiation is called thermal radiation and has a lower frequency than solar radiation. Because it has a lower frequency, some of it is captured by carbon dioxide and can’t escape into space. It is this extra radiation that can’t get back to space that is causing the planet to warm.
You can see that the average global temperature has only increased by about two degrees Fahrenheit since 1880. This doesn’t seem like much, but when you consider the entire surface area of the Earth – almost 200 million square miles – it adds up to quite a bit. The heat that is being added is equivalent to the heat produced by blowing up five Hiroshima-size atomic bombs every second. That’s a huge amount of heat. The reason that the surface temperature isn’t even warmer is because over 90% of this heat is being absorbed by the oceans. Water is denser than air and can hold much more heat, but the heat in the ocean acts as a thermal regulator for the planet and has a big impact on the weather. Warm water is what powers hurricanes, so we are experiencing more storms. In addition, both the warmer water and carbonic acid produced by dissolved carbon dioxide has an adverse effect on marine life. This has already killed half of the Great Barrier Reef and threatens phytoplankton, microscopic marine life that is responsible for producing about half of the world’s oxygen.
Most of the damage has been done in the past 50 years. Since the 1970s, the population of the Earth has doubled and annual carbon dioxide emissions have more than doubled, rising from 19 billion tons to over 43 billion tons. After a brief decline in 2021 due to the effects of the COVID pandemic, emissions are once again on the rise. Fossil fuel companies still receive over $15 trillion dollars in subsidies from world governments, so they have every incentive to continue to produce more and more gas, oil, and coal.
Also, during the past 50 years, the world’s wild animal population has decreased by 70%. This doesn’t mean that 70% have gone extinct, but the normal extinction rate is now estimated to be 100 to 1000 times normal. This has caused naturalists to declare that we are now in the midst of the worlds 6th mass extinction. The previous one was 65 million years ago when an asteroid collided with the Earth and killed the dinosaurs. Wild animals are not just something that we can appreciate aesthetically. Humanity is part of the ecosystem and depends on it remaining in balance. We are destabilizing it, and that will have adverse effects on us. Humans and their cattle now represent 95% of the mammalian biomass on the planet.
We have heard a great deal about wind and solar as a clean alternative to fossil fuels, but the stark reality is that, even after years of growth, wind and solar contribute only about 3% of the world’s energy needs. The problem is that it takes literally millions of solar and wind farms to replace the energy of fossil fuels, and we can’t build them fast enough to make much of a difference. And because they only have a useful lifetime of about 30 years, they would eventually have to be replaced as fast as they are being built just to stay even. Despite all the talk, wind and solar will not be able to supply our energy needs.
Nuclear fission now provides about 4% of the world’s energy needs. It has not grown much in the past two decades because the public has unreasonable safety fears about it. As the problems with fossil fuels increase, it will probably come back into favor, but new nuclear plants can take anywhere from ten to twenty years to go from the drawing board to actually producing power, so it does not offer short term relief. And nuclear power plants also have a limited lifetime – optimistically 50 years – and so they will also have to be replaced.
Despite a great deal of publicity over the past 50 years, nuclear fusion is still in the R&D stage. The largest experimental plant – ITER – is located in France and is being funded by an international consortium. It is years behind schedule and billions of dollars over budget. Construction started in 2014. It is supposed to have its first live test in 2025. If that goes well, it will be followed by ten more years of feasibility testing. By 2035, we will know if it is successful. If it is, construction will begin on actual power plants, since ITER is not designed to generate power for external use. The problem, once again, is that we have run out of time. We need to stop fossil fuel emissions as soon as possible. The UN Intergovernmental Panel on Climate Change (IPCC) is where all climate research comes together and goals are set. The IPCC has said that, in order to avoid drastic consequences, the world must reduce fossil fuel emissions by 50% by 2030 and eliminate them entirely by 2050. We are nowhere near achieving this objective.
Because the prospect of meeting the emission reduction targets looks so poor, research has begun on projects that could reduce their impact. One is carbon capture. Carbon capture can be conducted in two ways. The more effective way is to have scrubbers in the smokestacks of power plants to trap the carbon dioxide before it gets into the air. This is now happening on a limited scale, but the carbon dioxide is pumped back into old oil wells to force out the last dregs of oil they contain. Thus, the carbon capture results in producing more emissions, and the carbon dioxide that is pumped into the wells is not safely confined underground and eventually works its way back to the surface and into the atmosphere, so nothing has been gained.
The other method of capturing carbon dioxide is to remove it from ambient air. There are a few small plants that are doing this. The problem with it is that it takes energy to power the fans that capture the carbon dioxide and to pump the carbon dioxide into a safe storage facility, so, unless you can power the carbon capture facility with a clean energy source, the process is self-defeating. And, as noted previously, we have precious little in the way of clean energy sources. The largest clean energy source is hydroelectric power which produces 16% of the world’s electricity. But since electricity represents only 20% of the world’s total energy demand, hydroelectric provides a little over 3% of the total global energy demands – about the same as wind and solar combined.
Another project that is being considered is blocking the Sunlight by injecting small particles – aerosols – into the atmosphere. The atmosphere already has a considerable amount of aerosols that come from coal power plants. They have a cooling effect, but this effect has not been extensively studied because we don’t have the satellite technology to do so. The are many problems with this idea. One is that that most effective aerosol, sulfates, produce acid rain that damage the environment. Another is that they fall out of the air and so would have to be constantly replenished. A third problem is that they have to be injected into the stratosphere. We currently have no cargo aircraft with the capability to fly that high, so this technology would have to be developed. And the fourth problem is that the effort could have unanticipated effects, particularly on a local basis, since we know so little about how these aerosols behave.
Meanwhile, our situation continues to deteriorate. The summer Arctic Ocean ice diminishes every year, glaciers around the world are melting at a record pace, the Greenland Ice Cap is melting faster than anyone expected, and Antarctic Sea ice is melting at a record pace. This sea ice is what hold back the land-based glaciers. Once the sea ice is gone, there is nothing to keep the glaciers from flowing into the ocean. There is an enormous amount of ice in Greenland and Antarctica, and so it won’t melt overnight. But every revised estimate has resulted in an increased estimate of sea level rise. For a long time, experts thought that global sea level would rise by one or two feet by the end of the century. It is not expected to reach that level by 2050. This will have major consequences on coastal cities where 40% of the world’s population is located.
As the ice melts, the reflectivity or albedo of the Earth is reduced. This means that the Earth reflects less Sunlight, which accelerates the warming process. This is an example of a positive feedback loop. One process triggers another process which accelerates global warming. Methane is another example of this process. As the permafrost in the Arctic melts, the frozen methane which has been safely trapped underground begins to sublimate and escape into the atmosphere. Methane is twenty-five times stronger than carbon dioxide at trapping heat. There has been a sharp uptick in atmospheric methane over the past four years, primarily due to the oil and gas industry. Methane levels are now two and a half times what they were in pre-industrial times compared to carbon dioxide which is 50% higher.
Given this depressing state of affairs, talk has turned increasingly to adaptation. One way we can and should be adapting is by using less energy, but energy austerity is not a politically viable option for governments. It will take more damaging impact from the changing climate to move leaders to take unpopular steps. This highlights the unequal impact that climate change is having on the world population. People in the tropics are already seeing their lives severely disrupted. This disruption will eventually migrate northwards and similarly destabilize life in the temperate zones. Given the accelerating pace of change, this is likely to happen sooner rather than later. The major problems that populations will face, in addition heat and rising sea levels, is food scarcity, as droughts and floods interfere with the production and distribution of food, scarcity of potable water due to droughts and the intrusion of sea water into aquifers, unemployment and public unrest as economies and governments are stressed, and the impact of what is likely to be massive climate migration.
These are serious issues. The scenario is so dire that many have taken to treating this as doomsaying. It will likely remain that way until the problems touch closer to home.