The Causes and Consequences of Global Warming

Although people have been talking about global warming for a few decades now, in the past few years the problem has ceased to be one that’s in the distant future, but had instead become an imminent reality that is no longer possible to ignore. As of 2017, temperatures were 0.9°C higher than the average for 1951-1980. 0.9°C – is this a lot or a little for our planet? According to NASA data, Arctic sea ice extent has been plummeting since the turn of the millennium, falling by 13.2% per decade relative to the 1981-2010 average.

Some 195 countries have signed the Paris Agreement on climate change, thereby recognizing the negative human impact on climate and the environment. Its goal now is to limit global warming to no more than 2°C above preindustrial levels, and to do everything possible to limit future temperature rise to 1.5°C. Solving the problem of global warming has ceased to be the domain of individual countries, and is now the concern of all humankind.

Why did this problem arise in the first place? Since the Industrial Revolution, the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). This is a greenhouse gas which traps heat from the Sun; although the Earth needs some greenhouse gases to remain habitable, there can be too much of a good thing, and even current levels already threaten to make the world much warmer than it currently is.

Left uninterrupted, global warming could result in catastrophic outcomes, such as:

  1. Global temperature rise. The planet’s average surface temperature has risen about 1.1°C since the late 19th century, a change driven largely by increased carbon dioxide and other human-made greenhouse gas emissions into the atmosphere.
  2. Frequent extreme weather events. The frequency of tornadoes is going up as well as heat waves, hurricanes, and droughts. As “once in a century” storms become “once in a decade” ones, more and more safety and prevention systems will begin to break down.
  3. Species loss. We are already living through the planet’s sixth mass extinction. As the world warms, entire ecological zones will shift north and upwards; the ones furthest north may be “pushed off the top of the world” entirely. Flora and fauna are not as mobile as humans, and will struggle to keep up; some species, such as polar bears, may either vanish entirely or lose their genetic distinctiveness by interbreeding with grizzlies (“grolar bears”).
  1. Shrinking ice sheets. The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA’s Gravity Recovery and Climate Experiment show Greenland lost 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per year between 2002 and 2006, while Antarctica lost about 152 cubic kilometers (36 cubic miles) of ice between 2002 and 2005.
  2. Sea level rise. Global sea level rose about 8 inches in the last century. The rate in the last two decades, however, is nearly double that of the last century

 

Is there anything we could do? Of course there is!

Significant decreases in CO2 emissions is only possible through a united effort of all the world’s major countries. The Paris Agreement delineated energy sources into two main types: Those that emit greenhouse gases, and those that don’t – that is, carbon-free energy sources, such as nuclear, wind, and solar energy. Moreover, the most effective energy mix would be a combination of nuclear power and renewables, because unlike the latter, nuclear power can produce stable baseload power, due to its independence from weather conditions.

The world’s climate has always been changing, based on the Earth’s orbital dynamics, the level of solar radiation, volcanic eruptions, and greenhouse effects. But the sheer speed of today’s changes is unprecedented. If we want to avoid extreme warming, or the vagaries of large-scale engineering, it is incumbent upon us to take urgent action, such as: increase fuel economies and energy efficiency, utilities decoupling, reforestation, and the replacement of dirty energy sources, such as coal, with clean energy sources.