Natural Causes Cannot Explain the Current Rapid Global Warming

Superfact 143: Climate Change has been happening for billions of years, and it had nothing to do with us humans. However, the experts on past climate are telling us that the current rapid global warming, or if you call it climate change, or climate disruption, is not natural but is caused by us. Understanding why they say this is crucial to understanding what is going on with climate.

The sharp spike in the global average temperatures towards the right side of the graph above is caused by us humans, chiefly by our burning of fossil fuels. A very common objection to this claim is “Climate has always changed”, or “I think it is a natural cycle”,  etc. Such statements dismiss out of hand the expertise of the scientists who are the experts on past climate and natural causes for climate change. They are nearly unanimously stating that natural causes cannot explain the current rapid global warming, and it is obvious why if you look at the evidence.

To quote Katherine Hayhoe, a well-known climate scientist : “Hi, I’m a climate scientist. You may know me from my greatest hits including, “No, it’s not a natural cycle,” “Yes, I know it’s been warmer before (and the only reason YOU know this is because we scientists told you so)”

The evidence that we humans are the cause for the current rapid global warming is certainly not limited to the fact that no known natural cause of climate change can explain the current global warming. There is plenty of direct evidence that we are the cause. However, the fact that we know that no natural cause of climate change can explain the current warming is obviously news to nearly half of the American public and therefore an important and surprising fact by itself. It is a super fact. The faulty assumption that the current rapid warming is “natural” prevents many from trying to understand the evidence that show that we are responsible for it.

Orbital Cycles are not the Cause of the current Global Warming

One type of important type of climate forcing that’s been the cause behind the multiple ice ages that we’ve had over the last two million years are earth’s orbital cycles, or the Milankovitch cycles. There are primarily three orbital cycles, orbital eccentricity, change in axial tilt, and axial precession. Could they be responsible for the recent climate disruption and sudden warming?

Changes in Eccentricity

Earth’s orbit is not a perfect circle. Earth’s orbit varies from nearly circular to slightly elliptical and this change can cause climate change. This shift in Earth’s orbit takes place over periods of about 100,000 and 400,000 years. Click on the video from NASA below for an illustration of Earth’s eccentricity.

Changes in Obliquity (Tilt)

The angle Earth’s axis of rotation is tilted as it travels around the Sun is known as obliquity. Obliquity is why Earth has seasons. Over the last million years, it has varied between 22.1 and 24.5 degrees with respect to Earth’s orbital plane. The greater Earth’s axial tilt angle, the more extreme our seasons are. In addition, a larger tilt angle favor periods of deglaciation. The changes of Earth’s obliquity have a period of 41,000 years. Click on the video from NASA below for an illustration of the changes in obliquity.

Axial Precession (Wobble)

Earth wobbles slightly as it rotates, like a slightly off-center spinning top. The axis of Earth’s wobble changes slowly and is called axial precession. The corresponding cycle spans 25,771.5 years, or approximately 26,000 years. Click on the video from NASA below for an illustration of the changes in axial precession.

Why Orbital Cycles are not the Cause of the current Global Warming

The reasons Earth’s Orbital Cycles cannot be responsible for the recent sharp uptick in average global temperature, and the associated climate disruption, are for example:

• The changes in Earth’s eccentricity take place over 100,000 to 400,000 years, The changes of Earth’s obliquity have a period of 41,000 years and Earth’s Wobble cycle is around 26,000 years. These cycles are hundreds of times longer than the sudden uptick in temperature that we are witnessing today.
• NASA and other organizations keep track of these cycles, and they are causing a slow cooling, not a sudden warming. Obviously, the cause for the rapid warming must be something else.
• Depending on what is causing a climate forcing the climate change / warming will happen in different ways. The different types of climate forcing have different fingerprints if you will. For example, we are seeing a “blanket effect”. The lower atmosphere is warming while the upper atmosphere is cooling as if the atmosphere is acting like a blanket. That is greenhouse gases, not orbital cycles or the sun.

To read more about why orbital cycles are not the cause of the current Global Warming click here.

The Sun is not the Cause of the current Global Warming

The Sun is not the cause of current global warming. According to data from NASA, solar energy output has shown no net increase since the late 1970s. In addition, the amount of solar energy Earth receives has followed the Sun’s natural 11-year cycle of small ups and downs with no net increase. Over the same period, global temperature has risen significantly. The current warming is driven by human-made greenhouse gases, not changes in the Sun.

The graph above compares global surface temperature changes (red line) and the Sun’s energy received by Earth (yellow line) in watts (units of energy) per square meter since 1880. The lighter/thinner lines show the yearly levels while the heavier/thicker lines show the 11-year average trends. Eleven-year averages are used to reduce the year-to-year natural noise in the data, making the underlying trends more obvious. You can read more about why the Sun is not the Cause of the current Global Warming, here or here or here.

In summary, the fluctuations in the sun radiance are much quicker than the orbital cycles. However, we still know that the Sun is not responsible for the current rapid global warming because the Sun’s energy output has shown no net increase since the late 1970s. In addition, the amount of solar energy Earth receives has followed the Sun’s natural 11-year cycle of small ups and downs with no net increase. We also know that Sun is not responsible for the current rapid global warming because if it was the Sun the upper atmosphere would not be cooling and the temperature increases would be distributed differently across Earth and distributed differently with respect to time. That’s the blanket effect again.

To read more about why the sun is not the cause of the current Global Warming click here.

Volcanoes emit a tiny fraction of carbon compared to humans

Volcanoes emit about 0.2 to 0.6 billion metric tons of carbon dioxide per year globally. Our burning of fossil fuels and industrial activities release more than 35 billion metric tons annually. Human emissions are roughly 60 to 100 times greater than all global volcanic output combined. Thus, volcanoes are not the cause of the current rapid global warming.

There are some wild and false claims on social media claiming that “a single volcanic eruption release as much CO2 as all of humanity has to date” Or even much more than that. As Snopes explains this is nonsense. As mentioned, volcanoes emit about 0.2 to 0.6 billion metric tons of carbon dioxide per year globally. Our burning of fossil fuels and industrial activities release more than 35 billion to 38 metric tons annually. Thus, volcanoes emit only a small fraction of CO2 compared to what we do burning fossil fuels. Which also means that volcanoes are not the cause of the current rapid global warming. You can read more about this here, or here, or here, or here.

To read more about why volcanoes cannot be the cause of the current Global Warming click here.

Carbon Cycle Emissions Does Not Cause Global Warming

There are a lot of natural carbon emissions from the soil, rotting plants, animal and human respiration, and oceans, and a small amount from volcanoes. However, carbon is also absorbed by the oceans, and by plants via photosynthesis, etc., and this creates a balance that has existed for many thousands of years. This is called the carbon cycle. Despite the fact that the carbon emissions from burning fossil fuels are smaller than some of the naturally occurring carbon emissions mentioned, they are what is behind the increase of carbon in the atmosphere because they are a new addition that disrupts the balance.

You can read more about the carbon cycle and our recent human additions by clicking here. The explanations in that post are also better and more detailed.

Additional Points on Climate Change

Another related but different issue that confused a lot of people is the role of water vapor. Water vapor is responsible for roughly half of Earth’s total greenhouse effect, but only as an amplifier of what is caused by carbon emissions. Unlike carbon dioxide or methane, water vapor condenses and falls as precipitation. Water molecules only stay in the atmosphere for about two weeks. We do not directly control global water vapor levels. When carbon dioxide warms the planet the atmosphere holds more water vapor, which amplifies the initial warming. However, water vapor does not drive global warming. Carbon dioxide emissions and to a lesser degree methane emissions drive global warming.

How water vapor relates to the current global warming / climate change is cause for a lot of confusion. To get an understanding of this topic please click here.

Another thing to note is that even though ocean currents regulate global climate they are not the cause of the rapid Global Warming we are witnessing. El Niño events can combine with background global warming to temporarily increase global temperatures but is not the cause of the current rapid Global Warming. The cause for the recent rapid global warming is human activities, chiefly our greenhouse gas emissions. This in turn alters ocean currents and intensifies El Niño. You can read more about that here.

Another point worth noting is that Without the Burning of Fossil Fuels Earth would be cooling. You can read more about that here.

I can add that the evolution of new life forms, such as the evolution of Cyanobacteria and Plants, also resulted in significant climate change. In this case massive global ice ages. However, this played out during hundreds of millions of years, not 150 years.

Conclusion

In summary, no known natural causes can explain the current rapid global warming, and this fact is just one of the many pieces of evidence informing us that the current rapid global warming is chiefly due to us burning fossil fuels.

Other super facts related to global warming

• Global Warming is Happening and is Caused by us
• The Hockey Stick Graph is not Wrong
• Scientists Agree that Global Warming is happening and that we are the Cause
• Climate change worsens wildfires in the US
• Without carbon dioxide the Earth would freeze
• IPCC Did Not Backtrack on Global Warming Being Human Caused
• Orbital Cycles are not the Cause of the current Global Warming
• The Sun is not the Cause of the current Global Warming
• Volcanoes emit a tiny fraction of carbon compared to humans
• Climate change worsens wildfires Globally and human Land-Use Changes Reduces them
• Carbon Cycle Emissions Does Not Cause Global Warming
• The Most Important Greenhouse Gas Does Not Drive Global Warming
• El Nino or Ocean Currents are not the Cause of Global Warming
• Without the Burning of Fossil Fuels Earth would be cooling

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To see the other Super Facts click here