By Javier Rico
Neither at the 2015 United Nations Conference on Climate Change in Paris nor among the vast majority of the scientific community is there room for denial. According to the Intergovernmental Panel on Climate Change (IPCC), "it is extremely probable - more than 95% - that human influence is the dominant cause of the warming observed since the mid-20th century."
Skeptical scientists, who question mainly the more catastrophic consequences associated with climate change, do not want to be confused with the deniers, backed mainly by the more conservative wing of the US Republican Party and similar groups in Australia and Europe. Nor with pseudoscientific blogs. Some renowned skeptic, like Richard Muller, has come to assume that the phenomenon exists and has human origin. However, his earlier theories and those of other skeptics are dogma of faith to deniers.
Next, we review the most controversial arguments used by them.
Satellites of the US Oceanic and Atmospheric Administration (NOAA) detected an anomaly south of Greenland this summer that they called a great cold spot. In spring, researchers from the Scripps Institute of Oceanography at the University of California, who for years have confirmed the decline in Arctic ice and its impact on climate, doubted that this thaw was irreversible.
In 2011, a team of Danish experts also questioned the theory of no return on warming, finding evidence that ice pack levels in the Arctic Ocean were 50?% Lower 5,000 years ago. None of these investigations question the existence of climate change, but they serve the deniers to justify their positions and link them to the unusually cold temperatures of last summer in northern Europe, which in Ireland fell to levels unknown since 1986.
David Vieites, a researcher at the National Museum of Natural Sciences in Madrid, believes that "much remains to be known about the origin and consequences of this cold spot." The truth is that another study from November 2015 stipulates that Greenland's last stable glaciers, located so far north that they escaped the impact of climate change, have accelerated their melting in the last decade.
According to the deniers, the influence of our star and its activity - cosmic rays - on the origin of global warming is not sufficiently taken into account. And they claim that there is evidence that in recent centuries the temperature and number of sunspots on our star have increased and played a decisive role in the increasing heat on Earth.
However, there are divergences here, as all recent scientific studies point out that while the Earth follows an upward trend in its temperatures, the Sun shows the reverse trend. Papers presented in 2009 by Anatoli Erlykin of the Russian Academy of Sciences, together with other researchers from the Universities of Lancaster and Durham (UK), attributed 14?% Of the blame for the recent increase in solar activity to solar activity. average temperature of the Earth.
Other research, such as that of Benjamin Santer, from the Lawrence Livermore National Laboratory (US Department of Energy), highlights that if the influence of the sun were really so noticeable, the stratosphere would heat up more than the troposphere, the layer of the closest atmosphere to Earth. However, it happens the other way around, because even the top is getting cold.
The importance of the oceans and the currents that cross them to regulate the planet's climate is known. For this reason, deniers also believe that its ability to absorb both heat and carbon dioxide from the atmosphere has been underestimated. In addition, they cling to studies that periodically affirm or deny that this absorption capacity has already been exceeded, especially in the Antarctic Ocean.
It is true that, in general, the seas trap more CO2 than they release, which removes a part of that from human activities and slows down the effects of greenhouse gas emissions. The problem, according to the World Ocean Commission, is that "the sea absorbs more than 25% of CO2 emissions, causing it to acidify at unprecedented rates in the last three hundred million years."
According to NASA data, the sea ice that surrounds the Antarctic continent reached its maximum extent in December 2013. This gives rise to deniers to argue that if the planet's temperature rise occurs evenly, it would not make sense that Antarctica not only do not lose ice mass, but it grows in some places. One of the reasons to explain the phenomenon is that the strong winds of cold air that travel from the interior of the Antarctic territory towards the coast contribute to lower the thermometers and to thicken the marine icebergs.
Vieites also recalls that "the Antarctic, unlike the Arctic, which is a recently formed icy sea, is a continent that has been frozen for thirty million years, with ice sheets of several kilometers that hardly melt."
A team from the University of Bristol has published two studies in the magazines Science and The Cryosphere in which they highlight that numerous glaciers are thinning along 750 km of coastline. His conclusion is that West Antarctica is one of the regions of the Earth that suffers a faster and more unbalanced warming, since the ice that melts in the ocean is not compensated by snowfall.
The vast and cold eastern region of Russia, with its 13.1 million km2 (twenty-six times Spain), demands the attention of those who study climate change for several reasons. This is one of the main scenarios in which denialists and adaptationists intersect: admitted that there is an alteration in the climate - be it of human or natural origin - that entails a gradual rise in temperatures on the planet, it must be understood as a change for the better that should be taken advantage of.
Just as in Europe and in other developed countries we are thinking of reconverting our agriculture - there is talk of planting vines in England - thanks to the warmer weather, other parts of the world are starving due to a pressing drought or as a result of the rising sea , which floods lands and houses. The World Health Organization is one of the organizations that raises the voice about the perverse effects of global warming for people.
Alarmists, exaggerators and climatologists
These are some adjectives that the deniers put to the experts who hold the consensus on human responsibility in climate change.
Muller remains skeptical on other points and believes that it is far-fetched to attribute to climate change hurricanes such as Katrina, the speed of the melting of the Arctic or the retreat of Himalayan glaciers. In addition, he recalls that there have been other warm periods in history, such as the late Middle Ages. However, Vieites points out that by dendroclimatology –study of tree growth rings– “it is known that there was a substantial increase in temperatures, but not all over the planet, as it does now ”.
Regarding the data wielded by the deniers on the slowdown of the thermal increase in some years of this century, other experts argue that trends must be studied over long periods, and that we have never experienced similar rises in the thermometer in such a short space of time.
Regarding greenhouse gases, such as CO2, several studies reduce their responsibility on the subject. But a 2015 investigation by the US Pacific Northwest National Laboratory (PNNL) reveals that the predictions on the rate of global warming raised so far may fall short, since the current one is faster than that produced naturally during the years. last thousand years.