For decades, the world has experienced increasingly rising temperatures resulting in global warming. In short, global warming expresses the continuing rise in the earth’s atmospheric and oceanic average temperatures. These high temperatures significantly affect the global climate systems. Global warming is responsible for the extreme climatic changes that have occurred in the last few decades. The world has experienced uneven rainfall patterns, extreme drought, and famine events, as well as frequent floods and hurricanes among others. Consequently, governments around the world have agreed to adhere to environmental agreements seeking to minimize greenhouse gas emissions and increase the use of cleaner energy resources. As the global climate interventions continue, another kind of debate has come up following recent revelations of a slowdown in global warming. The phenomenon scientifically regarded as a ‘hiatus’ is currently a point of debate as scientists continue to dismiss the claim citing a wide range of reasons. The paper argues against the slowdown in global warming and presents an opposing argument.
In a recent report, the Intergovernmental Panel on Climate Change (IPCC) evaluated the global surface temperatures in the last 15 yrs and stated that there was a clear slowdown in global warming. However, the statement has received significant criticisms because of its implications for current policies and efforts that governments have embarked on to minimize global warming and climate change. The statement that a slowdown in climate change occurred has attracted the attention of scientists around the world who dispute the existence of this occurrence. According to Wolfe, throughout the last 15 years, the average atmospheric and oceanic temperatures have continued to go up taking into account the various indicators of global warming. The oceans now capture a higher amount of the warmth in the atmosphere than expected. This is causing the warming of the deep water layers. The historical data currently reveal that more global warming is occurring in the global ocean systems leading to ocean warming, the principal cause of the rising sea level.
According to Readfearn, the argument that a slowdown in global warming is not true because the study that presented this conclusion used air temperature trends. It did not use the sea level rise, the growing incidents of heat extremes, and ocean temperatures. These factors pass as more reliable measures as compared to air temperatures alone when it comes to the evaluation of the global warming trends. It is so because oceans absorb much of the heat that the greenhouse gas emissions capture in the atmosphere. In addition, the rising sea level highlights the indirect impacts of global warming given that the sea level rises as a result of the increasing ocean temperatures. Therefore, it is clear that the conclusion should take ocean warming and sea level rise into consideration instead of evaluating air temperatures alone. Matt England, a professor at the University of New South Wales, states that the slowdown is false when global warming is measured in terms of the global climate system. Further, he cites the consistently rising ocean heat content as a manifestation that no slowdown occurred. It highlights the biases in the IPCC report and discredits the idea that a slowdown actually occurred in the global warming rates in the last 15 years.
O'Callaghan states that new research indicates that global warming rates in the 21st century remain as high as those experienced in the 20th century despite claims of a slowdown. The global warming rate was 0.113C per decade between 1950 and 1999 when compared to a rate of 0.116C per decade that occurred between 2000 and 2014. The figure is relatively higher in the past decade, despite claims that there was a slowdown within the same period. In fact, 14 out of the 16 hottest years experienced in the global climatic records have occurred in the period since 2000. The relatively high global warming rates and the hottest years all seem to have occurred in the period the IPCC report claimed experienced a slowdown. In recent investigations that used data from weather stations around the global, scientists have established that the slowdown never actually occurred as claimed. NOAA evaluated surface air temperatures coming from numerous weather stations all over the globe in land and sea. The conclusion was that global warming occurred at more than double the rate the IPCC reported.
The corrected analysis of the surface air temperatures indicates that global warming rates continued to rise. This is contrary to the previous observation in which some scientists claimed a slowdown occurred. According to Readfearn, the correction of the bias that was present in the data regarding ocean temperature used in the analysis, the slowdown that the IPCC report indicated vanished. So far, two research papers have discredited the existence of a slowdown based on the analysis of the most recent data. The research papers, one from Thomas Karl and another from Stephen Lewandowsky concluded that the slowdown in global warming did not occur based on the long-term trends. In these papers, the authors statistically and practically proved in inexistence of the so-called slowdown as indicated in the global warming rates and additional analysis devoid of the biases noted in the IPCC report. In reality, the period the IPCC report claimed to have gone through a slowdown experienced to relatively faster global warming when compared to the past 65 years. With this in mind, there is no possibility that a global warming slowdown can coincide with the hottest years and faster global warming.
Karl also notes that observational biases when it comes to global surface temperatures have a role to play in the idea that a slowdown occurred in global warming. The authors noted that residual data biases impacted the analysis of the air surface temperatures, which the IPCC used as a basis for the conclusion on the existence of slowdown. Unlike the IPCC, the NOAA analyzed the sea air surface temperatures and land air surface temperature from land stations, ships, and drifting surface buoys. The use of different sources of air surface temperature eliminated the observational biases attached to the analysis in the IPCC report. In addition, the conclusions in the IPCC report might not be true given that the organization used the Climate Research Unit data from the Hadley Centre that is deficient as a result of incomplete coverage of the area over the Arctic. This means that the data used in the analysis might have caused the underestimate of global warming, thus causing the notion that there was a global warming slowdown. Further, the global warming rates depend on start and end date of the analysis in which case bias occurs as indicated in the changes in the global trends with the addition of air surface temperatures for another two years. Therefore, the observational biases in the IPCC analysis played a significant role in reaching at the conclusion that the last 15 years experienced a slowdown.
On the other hand, the IPCC co-authors and opponents of the global warming slowdown oppose the arguments that the slowdown in global warming did not occur. Fyfe and Meehl believe that the slowdown is as a result of a decadal variability in which case the Pacific Decadal Oscillation (PDO) is responsible for the natural variance in the global warming trend. The proponents claim that the existence of colder ocean temperatures in the tropical Pacific causes the PDO to move to the negative causing the Pacific to cool down. As a result, this causes global warming to slowdown. Further, Fyfe asserts that the global warming slowdown is as a result of internal variability following incidences of strong volcanic eruptions such as the Mount Tambora eruption that have a cooling effect. Therefore, the proponents of the slowdown cited internal variability as a cause of the global warming slowdown. Even so, Matt England emphasizes that the decadal variability does not affect the long-term projections of global warming.
In conclusion, global warming is associated with the rise in the atmospheric and oceanic temperatures. However, a more recent report from the IPCC cited that a global warming slowdown has occurred in the past 15 years. The conclusion has become a source of debates among scientists who support and oppose the assumption based on the analysis of air surface temperature. NOAA recently published another report expressing that the global warming remained relatively high when compared to the last century. In fact, the period that IPCC report to have experienced the slowdown contains the years with the highest temperatures on record. The data the IPCC report used in the analysis is also conflicting due to incomplete coverage of a region over the Arctic. Further, observational biases are evident in the IPCC report. The evidence points out that the global warming slowdown did not occur at all as indicated in the IPCC report. In addition, Thomas Karl and Stephen Lewandowsky have presented updated research reports that dismiss the existence of this phenomenon.