Rapid changes in the global climate is a growing topic of concern worldwide. One important component of climate change is the trend in rising global temperatures. Though the use of indirect temperature measurements (such as tree rings and ice cores), unanimous conclusions have been made that average global surface air temperature has risen by a little over 1 degrees Fahrenheit since the beginning of the 20th century (National Academy of Sciences [NAS], 2014). While this change appears miniscule, data reveals that the past couple decades show warmer global temperatures than any other decade since the mid-19th century (NAS, 2014).
It is strongly suggested that human activities are the cause of recent observations in global warming (NAS, 2014; National Aeronautics and Space Administration [NASA], 2018). Emissions of greenhouse gases are noted to be a main factor in global warming. Since the Industrial Revolution, amounts of carbon dioxide, methane, and nitrous oxide have increased significantly (NAS, 2014). Increases in greenhouse gas emissions result in the absorption and emission of heat energy towards the earth’s surface. Ultimately, there is a warmer surface and atmosphere, contributing to the rise in global temperatures (NAS, 2014; United States Global Change Research Program [USGCRP], 2016).
The impacts of global warming are evident through recent environment transformations. These changes are seen in increasing ocean temperatures, shrinking ice sheets, glacial retreat, and rises in sea level (NAS, 2014; NASA, 2018). Climate change and global warming contribute not only to environmental changes, but it also poses a threat to human health. Increased global temperatures can bring rise to heat-related illnesses and deaths, increased vectors and risk of vector-borne infection, and water-related illnesses (USGCRP, 2016).
Two options for combatting climate changes include mitigation and adaptation. Mitigation involves reducing contributions to greenhouse gasses to minimize climate change while adaptation involves responding to climate change once the effects have occurred or in anticipation of the effects (Shalizi & Lecocq, 2009; Vanderheiden, 2011). In the past, immediate action towards the implementation of programs promoting mitigation or adaptation have been stunted – Either due to scientific uncertainties or discussions revolving the seriousness of the effects of climate change (Kerr, 2007). It is apparent by observing the recent trends in global warming that action towards global warming should not be waited on any further. The longer we wait the worse the effects will get. Immediate action towards global warming is necessary due to the changes in the environment, risks to human health, and the benefits of mitigation and adaptation.
Continuous Changes to the Environment
The environment continues to reveal changes due to global warming, warranting immediate action. As a result of increasing global temperatures, ocean temperatures are consequently increasing. After evaluating past and current data from the mid-20th century to the beginning of the 21st century, it was shown that there has been an increased warming of the upper 700 meters of the ocean since 1969 (Levitus et al., 2009).
The warming of the oceans negatively affects marine life and the aquatic ecosystem. Increased temperatures in global oceans have resulted in changes in the distribution of harmful algal bloom (HAB), which rely on sea-surface temperatures for controlling the distribution and range in coastlines and ocean basins (Gobler et al., 2017). Results from a study by Gobler et al. found that since the 1980s, increased temperatures in the North Atlantic and North Pacific oceans have resulted in increased growth rates of HABs and increased bloom seasons (Gobler at al., 2017). HABs contribute to the eutrophication of surface water, which negatively impacts marine life, human health, and the environment.
Increased ocean temperatures as a result of global warming also affects Earth’s ice melting and glaciers. Between 1993 and 2016, 281 billion tons of ice were lost per year in Greenland while 119 billion tons were lost in Antarctica (NASA, 2018). A study by Shepherd and Wingham found that Greenland and Antarctica contributed to 125 gigatons of ice per year as a result of an acceleration in ice flow from ice streams and glaciers (Shepherd & Wingham, 2007). In Antarctica specifically, the rate of ice loss has tripped in the last decade (NASA, 2018).
As a result of rising ocean water temperatures and melting glaciers and ice, sea levels across the globe are rising. The rise in sea level can be attributed to thermal expansion. Thermal expansion occurs when. Melting. However, some research concluded that although losses in Greenland and Antarctica’s ice provided sea-level contribution, it was an amount that would lead to a large contribution (0.35 mm a year) considering the current rate of sea-level rise (3.0 mm a year) (Shepherd & Wingham, 2007). Another study suggests that although Greenland, Arctic Canada, Alaska, and other areas around the world contributed to the greatest amount of ice mass in the 2000s, Antarctica produced little losses (Gardner et al., 2013). .