5 Planet-Changing Consequences of Global Warming
The following is an excerpt from the new book Climate Change For Beginners by Dean Goodwin (For Beginners, 2016).
Many of the consequences of enhanced global warming and climate change have been highlighted and discussed throughout the media, in television programs and newscasts, magazines and newspapers, radio broadcasts, blogs, Websites, and textbooks. The topic is probably the most widely publicized of any current environmental issue. Depending on the source of the information, and the particular bias of the author, some consequences have been downplayed while others have been sensationalized and exaggerated.
What do we know is happening now, and what could possibly occur in the future? It is clear that we are already seeing global environmental changes that are a direct result of enhanced global warming and climate change. What is unclear is the extent to which these changes may continue to occur, and the impact of other changes that are predicted to take place as a result of the ongoing warming trend. Of course, the extent of any or all of the consequences will depend on how quickly the issue of greenhouse gas emissions is addressed on a global scale. More rapid action will reduce these potential outcomes, while slower action will only lead to a worsening effect. The latest report from the IPCC (Intergovernmental Panel on Climate Change) clearly outlines some of the potential consequences of global warming, and these conclusions have been subject to the highest level of scientific scrutiny and consensus, with over 97 percent of climate scientists in agreement with the findings. So what is the current state of affairs according to the latest IPCC report?
The Temperature Is Rising
The Earth is getting warmer. We are witnessing some of the hottest years on record since the mid-1800s. The effect is global in nature with the land masses experiencing a faster increase in temperature than the oceans. The warming effect is also more pronounced farther north from the equator. The IPCC suggests that the 30-year time period from 1983 to 2012 could represent the highest temperature change in any 30-year time period in the last 1400 years. In fact, 13 out of the 15 warmest years on record have occurred since 2000. The temperature increase is behind the heat waves that have led to many deaths worldwide, such as the tens of thousands that occurred in Europe during the summer of 2003. In the United States and elsewhere it seems that each year the daily temperature record for many locations is broken. The new ones that are set sometimes end up being broken again in a short time period. In January 2015, both NASA and NOAA jointly released their global temperature data showing that 2014 was the hottest year on record to date, surpassing both the 2005 and 2010 records, marking a 38-year trend of consecutive years with above average global temperatures. When the data is in from 2015 it may even supersede 2014 as the hottest year on record! It is interesting to note that the last time a global record cold temperature was set was back in 1911.
According to the IPCC, it is likely that heat waves will become more frequent over most of the earth’s land masses. In fact, a heat wave in Southern Pakistan and India from mid-May to mid-July 2015 resulted in the deaths of 3,200 people. The summer of 2015 saw new national record high temperatures in New Delhi, India (May), Vancouver, British Columbia (June), and new July records were set in Kahului, Maui and San Francisco, USA, Madrid, Spain, Kitzingen, Germany, London, England, Melun, France, and Maastricht, The Netherlands. Conversely, in the Southern Hemisphere, New Zealand and Australia recorded some of the coldest winter temperatures ever during July 2015! June and July of 2015 saw the highest monthly summer temperatures ever recorded in the Northern Hemisphere! So what else is this global temperature increase bringing about?
A Global Meltdown
Snow cover on mountain ranges is decreasing. Sea ice in the Arctic and Antarctic is melting at rates even faster than some of the climate models once estimated. Ice on land masses such as Greenland and the Antarctic is melting, and glaciers are receding. Specific examples of this global meltdown include:
- ice caves in Cascades National Park, Washington
- snow cover on mountain peaks in China (Meili Snow Mountain) and Tanzania (Mount Kilimanjaro), and
- glaciers in the Himalayas (Chhota Shigri), Iceland (Breidamerkurjokull), the Swiss Alps (Tschierva), Patagonia (Upsala and Perito Moreno), Canada (Athabasca), and the United States (Boulder in Glacier National Park, Montana, and Muir and Riggs in Alaska).
This melting has caused an increase in the size of glacial lakes in mountainous regions, and altered the flow in glacial and snow-fed streams and rivers. People in many parts of the world are dependent on snowmelt from mountain ranges as their predominant source of drinking water. Changes in the flow rates of glacial and snow-fed rivers will ultimately create water shortages for those populations who are dependent upon them. The Rockies supply Los Angeles and Southern California; the Himalayas supply Northern India.
Melting of sea ice has been observed in both the Northern and Southern hemispheres. In the Arctic the ice cover is shrinking, and according to the IPCC the extent of Arctic sea ice may decrease by 20 percent by 2050 with some summers to be completely ice-free by that time.
Rising Sea Levels
As ice melts it can bring about a rise in sea levels worldwide. Water has many unique properties; one of them is that as it freezes it expands. Have you ever known anyone to suffer from burst water pipes in the winter? As the water becomes ice, it passes through a temperature where its volume increases and the pressure exerted on the pipes is strong enough to break them. When the ice becomes liquid the pipes leak as the water flows freely from them through the break. As the sea ice, icebergs, and ice shelves melt the global sea level will increase due to this thermal expansion of water. According to the IPCC, since 1993 sea levels have been rising at around 3.1 mm per year, a finding consistent with the enhanced global warming trend. The global mean sea level rose by around 0.19 m (about 7.5 inches) from 1901-2010. The melting water from the sea ice was part of the ocean before it froze, so when it melts the impact on sea level rise will not be as great as from ice that melts from land masses that comes mainly from precipitation.
The melting of land-based ice in glaciated areas such as Greenland, Antarctica, and snow-covered mountain peaks will have a far greater impact on global sea levels than the melting of sea ice. The glacial ice in Greenland is melting at such a rapid rate that it could result in extremely high sea levels, simply by adding water to the ocean. Chasing Ice, the award-winning documentary on climate change by National Geographic photographer James Balog and his team on the Extreme Ice Survey, clearly shows the rapid melting of the glaciers in Greenland and other parts of the world. Scientists estimate that if all the ice covering Greenland were to melt, it could raise sea levels by 21 feet worldwide!
Roughly half of the earth’s human population lives in coastal areas; the potential effects of sea-level rise could be devastating and widespread. Low-lying coastal plains would become flooded and submerged by the advancing seas. Homes that were on the coast will become submerged. Homes that were miles inland will become, for a while, homes by the sea until the sea advances past them and they become submerged as well. This scenario is not too far-fetched. On July 23, 2015, James Hansen and a group of 16 of the world’s leading climate scientists published a must-read discussion paper on the subject of ice melt, sea level rise, and superstorms. They state that the rise in sea level may be as much as 10 feet in the next 50 years, and even more after that time. In a discussion with the host of CNN’s Fareed Zakaria GPS the following Sunday morning Hansen, an Adjunct Professor at Columbia University’s Earth Institute, stated that “science is telling us we have an emergency that could wreak havoc on all of the coastal cities around the world.” When asked by Zakaria about what should be done about it, Hansen replied “we're going to have to reduce emissions as fast as practical.” When asked about how the skeptics would view the publication, Hansen acknowledged “That's the nature of science. That's the lifeblood of science. You always are skeptical of any new conclusion.” Perhaps the residents of Washington, DC do not realize that they live in what could become oceanfront property!
The global rise in sea level would affect many areas, including:
- The coastal United States, especially the states of Florida, Texas, North Carolina, and Louisiana
- The Netherlands
- Low-lying islands in the South Pacific and Indian Oceans (the Carteret Islands, and the Maldives)
- The Baltic shore of Poland, and
- The delta regions of Bangladesh.
The Effect on Biodiversity
The IPCC has determined with a high degree of confidence that “20–30 percent of assessed species are likely to be at increased risk of extinction . . . and could be as high as 40–70 percent if global temperatures continue to rise.” A report in the journal Science in May 2015 suggests that one in six of the world’s species faces extinction due to climate change. The extinction of the golden toad in Costa Rica has previously been linked to climate change that aggravated a deadly disease. Some of the world’s most vulnerable species include the Arctic ringed seal, the golden bowerbird of Queensland, Australia, the American pika, the HaleakalaÌ„ silversword found only on the island of Maui, Britain’s golden plover, and Namibia’s longlived quiver tree. In the past 40 years the world has lost around half of its animals due to pressures such as climate change, habitat loss, deforestation, pollution, and overfishing according to the World Wildlife Fund.
The Effect on Humans
Climate change has begun to have an impact on human health. It is likely that we will see changes in infectious diseases in some places. As the temperature increases, the range of disease-carrying or disease-causing insect vectors could change. For example, the mosquito and tsetse fly are now found living at higher altitudes in some parts of Africa. A warming globe could bring about the spread of diseases such as malaria that prior to the temperature changes were not a problem in certain regions. This is of particular concern if you happen to be a resident of Harare, Zimbabwe, or Nairobi, Kenya, as these two cities are at elevations that mosquitoes previously did not inhabit. Now these cities are at risk due to the migration of mosquitoes to the higher altitudes as the temperature warms. Time will tell how widespread the changes in infectious diseases will become. Higher carbon dioxide levels have been implicated in increased amounts of ragweed pollen. This could lead to detrimental effects for those who are susceptible to allergies and prone to respiratory distress caused by asthma.
The entire human population is vulnerable to the threats posed by climate change brought about by global warming, because everyone is susceptible to the effects of drought, flood, heat wave, disease, and famine. No one is immune from the risks posed by climate change.
From Climate Change For Beginners by Dean Goodwin, For Beginners LLC, 2016