What is even climate change?
"Climate change includes both the global warming driven by human emissions of greenhouse gases, and the resulting large-scale shifts in weather patterns."
That human activity has caused climate change is not disputed by any scientific body of national or international standing. The largest driver has been the emission of greenhouse gases, of which more than 90% are carbon dioxide (CO2) and methane. Fossil fuel burning for energy consumption is the main source of these emissions, with additional contributions from agriculture, deforestation, and industrial processes. Temperature rise is accelerated or tempered by climate feedbacks, such as loss of sunlight-reflecting snow and ice cover, increased water vapour (a greenhouse gas itself), and changes to land and ocean carbon sinks.
Because land surfaces heat faster than ocean surfaces, deserts are expanding and heat waves and wildfires are more common. Surface temperature rise is greatest in the Arctic, where it has contributed to melting permafrost, and the retreat of glaciers and sea ice. Increasing atmospheric energy and rates of evaporation cause more intense storms and weather extremes, which damage infrastructure and agriculture. Rising temperatures are limiting ocean productivity and harming fish stocks in most parts of the globe. Current and anticipated effects from undernutrition, heat stress and disease have led the World Health Organization to declare climate change the greatest threat to global health in the 21st century. Environmental effects include the extinction or relocation of many species as their ecosystems change, most immediately in coral reefs, mountains, and the Arctic. Even if efforts to minimize future warming are successful, some effects will continue for centuries, including rising sea levels, rising ocean temperatures, and ocean acidification from elevated levels of CO2.
Many of these effects are already observed at the current level of warming, which is about 1.1 °C (2.0 °F).
The Earth absorbs sunlight, then radiates it as heat. Some of this infrared radiation is absorbed by greenhouse gases in the atmosphere, and because they re-emit it in all directions part of the heat is trapped on Earth instead of escaping into space. Before the Industrial Revolution, naturally-occurring amounts of greenhouse gases caused the air near the surface to be about 33 °C (59 °F) warmer than it would have been in their absence. Without the Earth's atmosphere, the Earth's average temperature would be well below the freezing point of water.
Human activity since the Industrial Revolution, mainly extracting and burning fossil fuels (coal, oil, and natural gas), has increased the amount of greenhouse gases in the atmosphere.
Despite the contribution of deforestation to greenhouse gas emissions, the Earth's land surface, particularly its forests, remain a significant carbon sink for CO2. Natural processes, such as carbon fixation in the soil and photosynthesis, more than offset the greenhouse gas contributions from deforestation.
Effects of climate change
The environmental effects of climate change are broad and far-reaching, effecting oceans, ice, and weather. Changes may occur gradually or rapidly.
Since the 1950s, droughts and heat waves have appeared simultaneously with increasing frequency. Extremely wet or dry events within the monsoon period have increased in India and East Asia. Various mechanisms have been identified that might explain extreme weather in mid-latitudes from the rapidly warming Arctic, such as the jet stream becoming more erratic. The maximum rainfall and wind speed from hurricanes and typhoons is likely increasing.
Global sea level is rising as a consequence of glacial melt, melt of the ice sheets in Greenland and Antarctica, and thermal expansion. Between 1993 and 2017, the rise increased over time. Over the 21st century, the IPCC projects that in a very high emissions scenario the sea level could rise by 61–110 cm. Increased ocean warmth is undermining and threatening to unplug Antarctic glacier outlets, risking a large melt of the ice sheet and the possibility of a 2 meter sea level rise by 2100 under high emissions.
Climate change has led to decades of shrinking and thinning of the Arctic sea ice, making it vulnerable to atmospheric anomalies. While ice-free summers are expected to be rare at 1.5 °C (2.7 °F) degrees of warming, they are set to occur once every three to ten years at a warming level of 2.0 °C (3.6 °F), increasing ice–albedo feedback(a positive feedback climate process where a change in the area of ice caps, glaciers, and sea ice alters the albedo and surface temperature of a planet. Ice is very reflective, therefore some of the solar energy is reflected back to space.)
Higher atmospheric CO2 concentrations have also led to changes in ocean chemistry. An increase in dissolved CO2 is causing ocean acidification, harming corals and shellfish in particular. In addition, oxygen levels are decreasing as oxygen is less soluble in warmer water, with hypoxic dead zones expanding as a result of algal blooms stimulated by higher temperatures, higher CO2 levels, ocean deoxygenation, and eutrophication.
The greater the amount of global warming, the greater the risk of passing through ‘tipping points’, thresholds beyond which certain impacts can no longer be avoided even if temperatures are reduced. An example is the collapse of West Antarctic and Greenland ice sheets, where a certain temperature rise commits an ice sheet to melt, although the time scale required is uncertain and depends on future warming. Some large-scale changes could occur over a short time period, such as a collapse of the Atlantic Meridional Overturning Circulation, which would trigger major climate changes in the North Atlantic, Europe, and North America.
Nature and wildlife
Recent warming has driven many terrestrial and freshwater species poleward and towards higher altitudes. Higher atmospheric CO2 levels and an extended growing season have resulted in global greening, whereas heatwaves and drought have reduced ecosystem productivity in some regions. The future balance of these opposing effects is unclear.
Climate change has contributed to the expansion of drier climate zones, such as the expansion of deserts in the subtropics. Without substantial actions to reduce the rate of climate change, land-based ecosystems risk major shifts in their composition and structure. Overall, it is expected that climate change will result in the extinction of many species and reduced diversity of ecosystems.
The oceans have heated more slowly than the land, but plants and animals in the ocean have migrated towards the colder poles as fast as or faster than species on land. Just as on land, heat waves in the ocean occur more frequently due to climate change, with harmful effects found on a wide range of organisms such as corals, kelp, and seabirds. Ocean acidification threatens damage to coral reefs, fisheries, protected species, and other natural resources of value to society. Harmful algae bloom enhanced by climate change and eutrophication cause anoxia, disruption of food webs and massive large-scale mortality of marine life. Coastal ecosystems are under particular stress, with almost half of wetlands having disappeared as a consequence of climate change and other human impacts.
Effects of climate change
Regional impacts of climate change are now observable on all continents and across ocean regions, with low-latitude, less developed areas facing the greatest risk. The Arctic, Africa, small islands, and Asian megadeltas are likely to be especially affected by future climate change.
The WHO has estimated that between 2030 and 2050, climate change is expected to cause approximately 250,000 additional deaths per year, from malnutrition, malaria, diarrhea and heat stress. The human impacts include both the direct effects of extreme weather, leading to injury and loss of life, as well as indirect effects, such as undernutrition brought on by crop failures.
Various infectious diseases are more easily transmitted in a warmer climate, such as dengue fever, which affects children most severely, and malaria. Young children are the most vulnerable to food shortages, and together with older people, to extreme heat. The WHO has classified human health impacts from climate change as the greatest threat to global health in the 21st century.
Climate change is affecting food security and will increasingly do so in the future. Between 1981 and 2010 climate change decreased global mean yields of maize, wheat, and soybeans. Future warming could further reduce global yields of major crops. Crop production will probably be negatively affected in low-latitude countries, while effects at northern latitudes may be positive or negative. Up to an additional 183 million people worldwide, particularly those with lower incomes, are at risk of hunger as a consequence of these impacts. The effects of warming on the oceans impact fish stocks. Regions dependent on glacier water, regions that are already dry, and small islands are also at increased risk of water stress due to climate change.
Economic damage as a consequence of climate change may be severe. Climate change has likely already increased global economic inequality, and is projected to continue doing so. Most of the severe impacts are expected in sub-Saharan Africa and South-East Asia, where existing poverty is already exacerbated. The World Bank estimates that climate change could drive over 120 million people into poverty by 2030. Current inequalities between men and women, between rich and poor, and between different ethnicities have been observed to worsen as a consequence of climate variability and climate change.
Low-lying islands and coastal communities are threatened through hazards posed by sea level rise, such as flooding and permanent submergence. This could lead to statelessness for populations in island nations, such as the Maldives and Tuvalu. In some regions, rise in temperature and humidity may also be too severe for humans to adapt to.
- Forego Fossil Fuels
The first challenge is eliminating the burning of coal, oil and, eventually, natural gas. This is perhaps the most daunting challenge as denizens of richer nations literally eat, wear, work, play and even sleep on the products made from such fossilized sunshine, and citizens of developing nations want and arguably deserve the same comforts, which are largely thanks to the energy stored in such fuels. There are no perfect solutions for reducing dependence on fossil fuels (for example, carbon neutral biofuels can drive up the price of food and lead to forest destruction, and while nuclear power does not emit greenhouse gases, it does produce radioactive waste), but every bit counts. So try to employ alternatives when possible—plant-derived plastics, biodiesel, wind power—and to invest in the change, be it by divesting from oil stocks or investing in companies practicing carbon capture and storage.
- Infrastructure Upgrade
Buildings worldwide contribute around one third of all greenhouse gas emissions (43 percent in the U.S. alone), even though investing in thicker insulation and other cost-effective, temperature-regulating steps can save money in the long run. Electric grids are at capacity or overloaded, but power demands continue to rise, and bad roads can lower the fuel economy of even the most efficient vehicle. Investing in new infrastructure, or radically upgrading existing highways and transmission lines, would help cut greenhouse gas emissions and drive economic growth in developing countries. Energy-efficient buildings and improved cement-making processes (such as using alternative fuels to fire up the kiln) could reduce greenhouse gas emissions in the developed world and prevent them in the developing world.
- Move closer to work
Transportation is the second leading source of greenhouse gas emissions in the U.S. (burning a single gallon of gasoline produces 20 pounds of CO2). One way to dramatically curtail transportation fuel needs is to move closer to work, use mass transit, or switch to walking, cycling or some other mode of transport that does not require anything other than human energy. There is also the option of working from home and telecommuting several days a week.
- Consume less
The easiest way to cut back on greenhouse gas emissions is simply to buy less stuff. Whether by forgoing an automobile or employing a reusable grocery sack, cutting back on consumption results in fewer fossil fuels being burned to extract, produce and ship products around the globe.
Think green when making purchases. For instance, if you are in the market for a new car, buy one that will last the longest and have the least impact on the environment. Thus, a used vehicle with a hybrid engine offers superior fuel efficiency over the long haul while saving the environmental impact of new car manufacture.
Paradoxically, when purchasing essentials, such as groceries, buying in bulk can reduce the amount of packaging—plastic wrapping, cardboard boxes and other unnecessary materials. Sometimes buying more means consuming less.
- Be efficient
A potentially simpler and even bigger impact can be made by doing more with less. Citizens of many developed countries are profligate wasters of energy, whether by speeding in a gas-guzzling sport-utility vehicle or leaving the lights on when not in a room.
Good driving-and good car maintenance, such as making sure tires are properly inflated-can limit the amount of greenhouse gas emissions from a vehicle and, perhaps more importantly, lower the frequency of payment at the pump.
Similarly, employing more efficient refrigerators, air conditioners and other appliances, can cut electric bills while something as simple as weatherproofing the windows of a home can reduce heating and cooling bills. Such efforts can also be usefully employed at work, whether that means installing more efficient turbines at the power plant or turning the lights off when you leave the office.
- Eat smart (go vegetarian)
Corn grown in the U.S. requires barrels of oil for the fertilizer to grow it and the diesel fuel to harvest and transport it. Some grocery stores stock organic produce that do not require such fertilizers, but it is often shipped from halfway across the globe. And meat, whether beef, chicken or pork, requires pounds of feed to produce a pound of protein.
Choosing food items that balance nutrition, taste and ecological impact is no easy task. Foodstuffs often bear some nutritional information, but there is little to reveal how far a head of lettuce, for example, has traveled.
University of Chicago researchers estimate that each meat-eating American produces 1.5 tons more greenhouse gases through their food choice than do their vegetarian peers. It would also take far less land to grow the crops necessary to feed humans than livestock, allowing more room for planting trees.
Believe it or not, U.S. citizens spend more money on electricity to power devices when off than when on. Televisions, stereo equipment, computers, battery chargers and a host of other gadgets and appliances consume more energy when seemingly switched off, so unplug them instead.
Purchasing energy-efficient gadgets can also save both energy and money—and thus prevent more greenhouse gas emissions. To take but one example, efficient battery chargers could save more than one billion kilowatt-hours of electricity—$100 million at today's electricity prices—and thus prevent the release of more than one million metric tons of greenhouse gases.
Swapping old incandescent lightbulbs for more efficient replacements, such as compact fluorescents (warning: these lightbulbs contain mercury and must be properly disposed of at the end of their long life), would save billions of kilowatt-hours. In fact, according to the EPA, replacing just one incandescent lightbulb in every American home would save enough energy to provide electricity to three million American homes.
© 2020 Lili Zoltai
Ken Burgess from Florida on October 05, 2020:
It is a problem... but I see it as one more about man-made pollution than "climate change".
True "climate change" concerns are not being addressed by our governments, it is an excuse to regulate, tax, and control... not really attack the problems.
The first topic on their list would be the Industrial Meat Complex... most of all Beef.
They are cutting down the Amazon rainforest faster now than at any time in history... they say the Amazon Rainforest is the lungs of the world.
Where is the world pressure to keep Brazil from destroying the forest... for grazing land for their cows?
Its not going to matter whether or not we have become "fossil fuel free" if the Amazon forest no longer exists... and they wiped out 18% of the forest in just the last two years alone.
In a decade, the damage will be so extensive its is predicted the entire ecosystem will collapse, and the forest destroyed.
We are allowing Brazil to kill the entire world by destroying the forest for grazing land... where is the outcry? Where are the "save the world" types when it comes to a real issue like that?