We hear about the perils of global warming every day of our lives. It is an apocalyptic problem the world faces, and there is currently no clear solution in sight. Nonetheless, many people, from prominent political figures to members of our community, dispute its reality. Often we become angry at these outliers, however, their message is not wholly unjustified; we accept our approaching doom without enter stopping to ask: “Where is the proof?”
So, for once, let’s question what the experts tell us, and weigh up the evidence on both sides of the debate.
Is ice core data reliable?
Most of our temperature records come from measuring the gasses trapped inside cores of ice which have been left unmelted for hundreds of thousands of years. By studying the chemical compounds in the trapped air within the ice, scientists are able to determine the concentration of compounds in the atmosphere from which this air originally came. This is how records of carbon dioxide concentrations from millennia ago are determined.
The major flaw in ice core data, however, is that they are not “closed-systems”; ice is not completely airtight and so some air can circulate through pores in the ice, affecting the outcome of the data. The effects of pressure in deep ice aids in forcing air out, whilst water in these pores dissolving soluble gasses such as CO2, altering the outcome further. Skeptics conclude that ice core data is too unreliable to base data on, and therefore scientists’ claims of CO2 levels increasing are unjustified.
The scientific consensus argues against this, claiming that the quantity of samples from which ice core data is received is used to reduce errors, with CO2 levels from different ice cores proving incredibly similar, hence validating their research. Furthermore, ice core data is compared with other evidence collected, from written temperature records to the rings inside tree growth rings, in order to improve the reliability of said data. While future CO2 level predictions do not depend on ice core data, it serves to prove a point: the climate is sensitive to changes in its cycle and CO2 is greatly influencing it.
Are other temperature records reliable?
Some 90% of temperature recording stations are on land, whereas the Earth’s surface is 70% ocean. Temperature records are distorted by the heat generated by towns and cities, creating what is known as the “urban heat island effect”. Considering the positioning of the temperature-recording stations some believe current temperature records cannot be trusted.
The response to this is simply that the scientific community is aware of the distortion of records, and that filters have been designs to eliminate this effect, recording the correct temperature.
If we are to trust these temperature records the question remains, do they prove global warming?
Are CO2 levels linked with rising temperatures?
Because of its extreme weather, the Arctic is often used as a monitor of global climate, however, the temperatures there poorly reflect human CO2 emissions. Even in other parts of the world, temperature records show that, historically, CO2 levels rise around 800 years after temperature levels rise. Clearly these two factors are correlated, however, correlation does not always equal causation. Despite the grand claims of the change in our climate, scientists fail to include the fact that temperatures were actually higher than those of today during what is known as the “medieval warm period”, centuries before humanity began pumping greenhouse gasses into the atmosphere. It was hot enough for grapes to be grown in England, and yet scientists constantly play down the significance of this period. Surely this all points to human driven global warming being fake, a molehill for the media to make a mountain out of?
The counter argument for this is, of course, that skeptics fail to look at the bigger picture. A single graph in the Arctic which shows the rise of CO2 during the 1930’s does not equate to rising temperatures worldwide during that time period. Similarly, the medieval warm period was most likely a local warming rather than a global one; there is no evidence that this temperature rise was present in the southern hemisphere at all. In fact, records suggest that overall the earth was slightly cooler than today. A single area does not constitute for world wide proof.
What of the argument that CO2 levels rose after the temperature in the past? The scientific consensus does not claim that rising CO2 levels caused previous temperature rises, but rather that because of the greenhouse effect, CO2 is making earth’s natural temperature rises increase dramatically. Historical global warming cycles span around 5000 years. The afore mentioned 800 year CO2 lag only tells us that CO2 did not influence the first 16% of the warming cycle; the other 4200 years were likely caused by the greenhouse effect of CO2. In a normal warming cycle, the sun heats the earth and temperatures rise, causing the oceans to release vast amounts of CO2 creating a greenhouse effect which warms the earth further. It is this greenhouse effect which has been causing concern among the scientific community; as the continued expulsion of greenhouse gasses into the air manginfies this greenhouse effect, the temperature drasticly shifts. It is this sudden change that poses our greatest threat, opposed to the natural temperature changes we have seen in the past.
How long will our emissions stay in the atmosphere?
UN scientists claim that CO2 remains in our atmosphere for 50 to 200 years, but is this the case?
Our oceans are giant sponges, soaking up the CO2 than we continually pump into our atmosphere. Our oceans are vast enough to absorb up to 50 times the volume of CO2 as there currently is in our atmosphere – more than can be produced by all the fossil fuels on the planet. Within 5 to 10 years, all the CO2 produced will be absorbed into our oceans, meaning that the increase in global CO2 levels cannot be solely attributed to humans, as CO2 sinks have been draining what we have produced.
This sounds wonderful in theory, however, the ocean is not quite as absorbent as skeptics claim. It takes 5 to 10 years for the ‘shallow ocean’ to absorb CO2; dissolved gasses in the shallow ocean are prone to escaping back into the atmosphere. CO2 is lost to the atmosphere just as quickly as it is absorbed. For CO2 to be absorbed into the “deep ocean” the UN’s 50 to 200 year time frame is far more accurate. Moreover, as the oceans absorb greater and greater quantities of CO2, their capacity to dissolve the gas decreases; the oceans become saturated. To fully absorb atmospheric CO2 our oceans would require around 50,000 years; not the optimistic 5 to 10 years portrayed by the skeptics. Furthermore, what CO2 is absorbed causes harm to marine life; dissolved CO2 decreases the pH of our oceans causing harm to marine life, most notably the bleaching of corals.
What conclusions can we draw from this data?
Is humanity dangerously out of step with the natural cycle; our reckless desire for production creating a dangerously sudden change in global climate? Or is this talk of CO2 caused global warming just an alarmist fear-mongering tactic by the United Nations?
Take a step back, weigh up the evidence, and decide for yourselves.