The problem of global climate change is probably one of the most discussed matters in the environmental science domain, with many contradictory points of view. Numerous studies have been conducted on climate change with results ranging from apocalyptic scenarios to scenarios that suggest that there is no increase in global average temperature in the last few decades.

To start off with, it is natural and normal to have variances on average temperature and greenhouse effect gasses (GHG). The annual average temperature and GHG concentrations in the present are considered to be far below the levels believed to have been the absolute maximum. Measurements in the past decades indicate that GHG concentrations (especially CO₂) have had an increasing trend, but it is uncertain if it is such a concerning matter as the mainstream multimedia advertises it and the concern about the temperature increase is even more exaggerated.

An example regarding these contradicting theories would be the studies conducted by Mann et al. in 1998 and McIntyre and McKitrick in 2003. The former study suggests that the average global temperature has been had a drastic increase since the industrial revolution and even more from 1950 onwards, while the latter suggests that the temperature has increased since 1850 but had insignificant variations since the 1950s (Etiope, 2016). Another example that questions whether the global warming is actually real is a study published by Anthony Watts in 2009 called “Is the U.S. surface temperature record reliable?”. In this study, Watts addresses the methodology used for temperature monitoring in the United States, demonstrating that a high percentage of the monitoring stations are inappropriately positioned: “In other words, 9 of every 10 stations are likely reporting higher or rising temperatures because they are badly sited” (Watts 2009). Many of these stations are placed near air conditioning units exhaust fans, concrete structures or other similar sources of heat or materials that retain heat. In conclusion, the study proves that the US surface temperature is not a reliable source of information when analyzing global climate change. According to this fact, it is difficult to interpret the data sets of NOAA (2016a) that suggests positive temperature anomalies with an almost linear increasing trend from 1950s until the current period. And another problem that should be taken into consideration is the fact that despite the positioning of the measurements stations not being proper, recording increased temperatures annually could still suggest that global average temperature increase might be a possibility, thus improvement of measuring methodology is required.

Another important aspect of global climate change is the variance of precipitation. Different data sources for this subject do not suggest such differences as with the case of global average temperatures. For example a comparison of the data provided by the Environmental Protection Agency in the United States (US EPA) and the data provided by Climate Data Information suggests that the two sets of data are reporting similar variations with slight differences. From the precipitation data on the US EPA website, citing the National Oceanic and Atmospheric Administration (NOAA, 2016b) it can be observed that recorded precipitation anomalies in the last century have had maximum variation of ±13 mm in the United States and ±5 mm on a global level. From the map presented on the US EPA website it is obvious that a substantial increase in annual precipitation has occurred in most areas of the United States with a few exceptions that recorded a considerable decrease, especially Arizona, California and slightly Nevada and Utah (US EPA 2016). The most significant increases in average precipitation quantities in the United States have been reported in the mid-eastern part of the country, especially Vermont, Michigan and a small portion of Washington.

An analysis of the simulation provided by Climate Data Information suggests that the mean precipitation quantities vary within a restricted margin as opposed to the observed data provided by Climatic Research Unit of University of East Anglia (CRU, 2015). However this data was recorded only until 1998, thus the last 2 decades are not present in the measurements as well as the simulation. A notable fact is that the observed annual precipitations have been on an increasing trend until the late 1970s and a decreasing trend can identified afterwards. A comparison between the recorded data and the simulation determines a considerable difference between the two sets, the simulation having a nearly linear trend without any significant variations.

Another aspect that is usually take into consideration in discussions about global climate change is the occurrence of natural disasters. The data provided is contradictory in this case, some studies suggesting an increase while other studies suggesting a steady average with some variations. The International Federation of Red Cross and Red Crescent Societies (IFRC) provide a table of all reported natural disasters since 2004. From the data it can be observed that the trend is decreasing in the monitored period. In accordance to this trend, the number of people killed in catastrophic events has drastically decreased, but it is not correlated with the number of people affected due to many unpredictable variables. It can also be observed that disasters related to weather conditions such as floods or extreme temperatures have generally had an decreasing trend with some spikes, the extreme temperatures occurrence in 2012 to be noted. It is not the case with windstorms, which have had an increase in number from 2011 to 2013. From the information provided by Max Roser (2016) on the Our World in Data website  it can be observed that the reported natural disasters have been increasing at an alarming rate since the 1960s, but this fact can probably be explained by the development of communication means and it is also a high probability that the definition of natural disaster has been different over the monitored period. The data shows a decrease similar to the trend from 1960 onwards since 2000. The number of people killed has had a decreasing trend regardless of natural disaster occurrence, with the exception of a spike in the first decade of the 20^th century, but the number of people affected has been in accordance with the number of catastrophes. From 2000 and afterwards the two trends are not in correlation, more people reported being affected in spite of a decrease in the number of natural disasters. Some differences can be observed between the data provided by IFRC and Roser especially when taking into consideration the trend of affected people. The IFRC report contains more detailed information making it clear that the most affected region is the Asian continent. However, both data sets clearly suggest that people affected by natural disasters have adapted well to the dangerous situations at which they are exposed, hence the decreasing trend of number of killed people as opposed to the number of people affected.

Taking into account that actual data for temperature and precipitation has been recorded only since the 19^th century and the fact that prior to period the average temperatures and precipitation have been measured trough indirect methods: “Indirect ways of assessing past temperatures, using so-called temperature proxies, take measurements of responses to past temperature change that are preserved in natural archives such as ice, rocks and fossils” (The Guardian, 2012). One of these methods is measuring chemical differences that appear in snow or ice formed at different temperatures. In other words, the temperature measurements taken with thermometers are not directly comparable with the measurements that reflect the temperatures in the prehistoric ages. It is the same case with historical CO­₂ measurements that require several ice core samples to be crushed under vacuum conditions and analyzed using a laser detector or a gas chromatograph. If the indirect measurements reflect the reality it is safe to assume that the temperatures and CO₂ levels measured in the present are far below the maximum levels measured in the prehistoric eras. The average temperature has had nearly cyclic variations since the Precambrian (Scotese, 2002), and the present period is considered to be cold in comparison to other, Triassic or Devonian for example, thus an increase in the global average temperature should naturally be expected.

One of the most important aspects that should be understood is the fact that the climate is constantly changing with or without human interference. The human race has been able to adapt and survive all the challenges it has faced and is the most developed species due to its ability to overcome all favorable and unfavorable circumstances. In the years to come the life of the average person could be changed by the climatic variations but it is a certain fact that is unavoidable. The uncertainty is when severe changes are going to occur, but the data that is available today suggests that significant changes are unlikely in the short term. Focus on reducing CO₂ emissions is debatable, as efforts in reducing other types of pollution such as particulate matter, sulfates, nitrates and atmospheric ozone should be a more pressing matter.

As a final conclusion, humans should do all that is possible to reduce their influence on the natural climatic change as much as possible and to analyze these variations in detail in order to be able to adapt properly to the permanently changing conditions of the climate.

References:                             

Anthony Watts, “Is the U.S. Surface Temperature Record Reliable?” Chicago, IL: The Heartland Institute, 2009.

Climate Data Info, http://www.climatedata.info/precipitation/global-simulation/, accessed October 12, 2016

Climatic Research Unit, University of East Anglia, https://crudata.uea.ac.uk/cru/data/precip/, accessed October 12, 2016

Etiope, G., “Global environmental changes course”, Faculty of Environmental Science and Engineering, Babeș Bolyai University, Cluj-Napoca, 20-22 April 2016

International Federation of Red Cross and Red Crescent Societies, World Disasters Report – 2014, http://www.ifrc.org/world-disasters-report-2014/data, accessed October 12, 2016

Max Roser (2016) – ‘Natural Catastrophes’. Published online at OurWorldInData.org. Retrieved from: https://ourworldindata.org/natural-catastrophes/, accessed October 12, 2016

NOAA (National Oceanic and Atmospheric Administration). 2016a. National Centers for Environmental Information, http://www.ncdc.noaa.gov/cag/time-series/global/globe/land_ocean/ytd/12/1880-2016, accessed October 12, 2016

NOAA (National Oceanic and Atmospheric Administration). 2016b. National Centers for Environmental Information, http://www.ncdc.noaa.gov/cag/time-series/us, accessed October 12, 2016

Scotese, R. C., http://www.scotese.com/climate.htm, 2002, accessed October 13, 2016

The Guardian, https://www.theguardian.com/environment/2012/mar/07/past-climate-temperature-proxies, accessed October 13, 2016

United States Environmental Protection Agency, https://www.epa.gov/climate-indicators/climate-change-indicators-us-and-global-precipitation#ref1, accessed October 12, 2016