Climate Change -- Causes -- Effects and Solutions

What is the difference -- Climate Change vs. Global Warming

Charney used "climate change." Definitions Global warming: the increase in Earth’s average surface temperature due to rising levels of greenhouse gases. Climate change: a long-term change in the Earth’s climate, or of a region on Earth. Within scientific journals, this is still how the two terms are used. Global warming refers to surface temperature increases, while climate change includes global warming and everything else that increasing greenhouse gas amounts will affect. During the late 1980s one more term entered the lexicon, “global change.” This term encompassed many other kinds of change in addition to climate change. When it was approved in 1989, the U.S. climate research program was embedded as a theme area within the U.S. Global Change Research Program.soure

But temperature change itself isn't the most severe effect of changing climate. Changes to precipitation patterns and sea level are likely to have much greater human impact than the higher temperatures alone. For this reason, scientific research on climate change encompasses far more than surface temperature change. So "global climate change" is the more scientifically accurate term. Like the Intergovernmental Panel on Climate Change, we've chosen to emphasize global climate change on this website, and not global warming. ..source

 

Greenhouse gas emissions (and other human activities) are radically transforming the planet on which we live. source...As a result, California's wildfire season is getting longer; thawing permafrost has destabilized Russian infrastructure; and yes, most of the world's glaciers are swiftly retreating. With public concern on the rise, two relevant terms have entered the lexicon: "Climate change" and "global warming." These are often treated like synonyms, but they have different meanings.

he National Oceanic and Atmospheric Administration (NOAA) reports that between the years 1880 and 2016, our home planet's average surface temperatures increased to the tune of 1.71 degrees Fahrenheit (0.95 degrees Celsius). source

https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature

How is climate change measured over time?

Earth-orbiting satellites, remote meteorological stations, and ocean buoys are used to monitor present-day weather and climate, but it’s paleoclimatology data from natural sources like ice cores, tree rings, corals, and ocean and lake sediments that have enabled scientists to extend the earth’s climatic records back millions of years. These records provide a comprehensive look at the long-term changes in the earth’s atmosphere, oceans, land surface, and cryosphere (frozen water systems). Scientists then feed this data into sophisticated climate models that predict future climate trends—with impressive accuracy.

 

What causes climate change?

The mechanics of the earth’s climate system are simple. When energy from the sun is reflected off the earth and back into space (mostly by clouds and ice), or when the earth’s atmosphere releases energy, the planet cools. When the earth absorbs the sun’s energy, or when atmospheric gases prevent heat released by the earth from radiating into space (the greenhouse effect), the planet warms. A variety of factors, both natural and human, can influence the earth’s climate system.

Natural causes of climate change

As we all know, the earth has gone through warm and cool phases in the past, and long before humans were around. Forces that contribute to climate change include the sun’s intensity, volcanic eruptions, and changes in naturally occurring greenhouse gas concentrations. But records indicate that today’s climatic warming—particularly the warming since the mid-20th century—is occurring much faster than ever before and can’t be explained by natural causes alone. According to NASA, “These natural causes are still in play today, but their influence is too small or they occur too slowly to explain the rapid warming seen in recent decades.”

Anthropogenic causes of climate change --Humans

more specifically, the greenhouse gas (GHG) emissions we generate—are the leading cause of the earth’s rapidly changing climate. Greenhouse gases play an important role in keeping the planet warm enough to inhabit. But the amount of these gases in our atmosphere has skyrocketed in recent decades. According to the Intergovernmental Panel on Climate Change (IPCC), concentrations of carbon dioxide, methane, and nitrous oxides “have increased to levels unprecedented in at least the last 800,000 years.” Indeed, the atmosphere’s share of carbon dioxide—the planet’s chief climate change contributor—has risen by 40 percent since preindustrial times.

The burning of fossil fuels like coal, oil, and gas for electricity, heat, and transportation is the primary source of human-generated emissions. A second major source is deforestation, which releases sequestered carbon into the air. It’s estimated that logging, clear-cutting, fires, and other forms of forest degradation contribute up to 20 percent of global carbon emissions. Other human activities that generate air pollution include fertilizer use (a primary source of nitrous oxide emissions), livestock production (cattle, buffalo, sheep, and goats are major methane emitters), and certain industrial processes that release fluorinated gases. Activities like agriculture and road construction can change the reflectivity of the earth’s surface, leading to local warming or cooling, too.

Methane

Methane is emitted from a variety of anthropogenic (human-influenced) and natural sources. ... Methane is the second most abundant anthropogenic GHG after carbon dioxide (CO2), accounting for about 20 percent of global emissions. Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere.

 

Methane is emitted from a variety of anthropogenic (human-influenced) and natural sources. Anthropogenic emission sources include landfills, oil and natural gas systems, agricultural activities, coal mining, stationary and mobile combustion, wastewater treatment, and certain industrial processes. Methane is the second most abundant anthropogenic GHG after carbon dioxide (CO2), accounting for about 20 percent of global emissions. Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere. Over the last two centuries, methane concentrations in the atmosphere have more than doubled, largely due to human-related activities. Because methane is both a powerful greenhouse gas and short-lived compared to carbon dioxide, achieving significant reductions would have a rapid and significant effect on atmospheric warming potential.

China, the United States, Russia, India, Brazil, Indonesia, Nigeria, and Mexico are estimated to be responsible for nearly half of all anthropogenic methane emissions. The major methane emission sources for these countries vary greatly. For example, a key source of methane emissions in China is coal production, whereas Russia emits most of its methane from natural gas and oil systems. Oil and gas systems are the largest source of U.S. methane emissions (29 percent), followed by livestock enteric fermentation (26 percent).

Methane remains in the atmosphere for 12 years until it is broken down into CO2

Importance of Methane

 

What is Causing the Recent Rise in Methane Emissions?

Researchers are now saying say that, globally at least, the increase in recent years is due to the activities of microbes in wetlands, rice paddies, and the guts of ruminants.

Evidence from carbon isotopes implies that the primary cause of the new growth is an increase in biogenic emissions, probably from wetlands and also agricultural sources, such as rice fields and cattle. source https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GB005406

Though our planet’s forests and oceans absorb greenhouse gases from the atmosphere through photosynthesis and other processes, these natural carbon sinks can’t keep up with our rising emissions. The resulting buildup of greenhouse gases is causing alarmingly fast warming worldwide. It’s estimated that the earth’s average temperature rose by about 1 degree Fahrenheit during the 20th century. If that doesn’t sound like much, consider this: When the last ice age ended and the northeastern United States was covered by more than 3,000 feet of ice, average temperatures were just 5 to 9 degrees cooler than they are now.

Why Is 1.5 Degrees the Danger Line for Global Warming?

When we talk about 1.5 degrees of warming, we’re talking about the increase in the Earth’s average temperature. We measure this increase from a baseline average temperature in the mid-to-late nineteenth century – when the Industrial Revolution swung into high gear and people began burning fossil fuels on an unprecedented level, jumpstarting climate change. https://www.climaterealityproject.org/blog/why-15-degrees-danger-line-global-warming

The important thing to understand is that global warming that comes from burning fossil fuels is not a uniform process. Due to a host of natural factors, some areas – like the poles – are warming much faster than others. So when we talk about preventing 1.5 degrees of global warming, we’re talking about preventing a 1.5 degree increase in the Earth’s average temperature. Some places have already crossed that line.

NOAA: Arctic warming at twice the rate of the rest of the planet --According to the report, surface air temperatures in the Arctic are warming at a rate twice as fast as warming across the rest of the planet, and the last twelve months were no exception.

Effects of Climate Change

Blame its cascading effects: As climate change transforms global ecosystems, it affects everything from the places we live to the water we drink to the air we breathe.

Extreme Weather

Dirty Air

Health Risks -- s global temperatures rise, so do the number of fatalities and illnesses from heat stress, heatstroke, and cardiovascular and kidney disease. As air pollution worsens, so does respiratory health—particularly for the 300 million people living with asthma worldwide; there’s more airborne pollen and mold to torment hay fever and allergy sufferers, too.

Rising Seas

Warmer, more acidic oceans

Imperiled Ecosystems

Solutions -- Two Parts Needed

The central objective of the Paris Agreement is its long-term temperature goal to hold global average temperature increase to “well below 2°C above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels”.

1- shifting away from dirty fossil fuels and toward cleaner, smarter energy --Renewable energy is now cheaper than fossil-fuelled generation in most of the world and renewables offer a faster and cheaper way to increase access to affordable clean energy for millions of people.

Renewable energy

Solar

Wind

Biomass --Biomass is considered a renewable energy source because its inherent energy comes from the sun and because it can regrow in a relatively short time. Trees take in carbon dioxide from the atmosphere and convert it into biomass and when they die, it is released back into the atmosphere. --Biomass, a renewable energy source derived from organic matter such as wood, crop waste, or garbage, makes up 4.8 percent of total U.S. energy consumption and about 12 percent of all U.S. renewable energy. Wood is the largest biomass energy source. In the U.S., there are currently 227 biomass plants operating. In the U.K., 35 are operating, 15 are under construction and 17 have been proposed. But just how renewable is biomass energy?

Biodiesel: A fuel typically made from soybean, canola, or other vegetable oils; animal fats; and recycled grease. It can serve as a substitute for petroleum-derived diesel or distillate fuel. For EIA reporting, it is a fuel composed of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, designated B100, and meeting the requirements of ASTM (American Society for Testing materials) D 6751.

Biomass is organic material that comes from plants and animals, and it is a renewable source of energy. Biomass contains stored energy from the sun. Plants absorb the sun's energy in a process called photosynthesis. When biomass is burned, the chemical energy in biomass is released as heat. Biomass can be burned directly or converted to liquid biofuels or biogas that can be burned as fuels. Examples of biomass and their uses for energy Wood and wood processing wastes—burned to heat buildings, to produce process heat in industry, and to generate electricity Agricultural crops and waste materials—burned as a fuel or converted to liquid biofuels Food, yard, and wood waste in garbage—burned to generate electricity in power plants or converted to biogas in landfills Animal manure and human sewage—converted to biogas, which can be burned as a fuel -- SOURCE

 

Biodiesel is a renewable fuel Biodiesel is a renewable fuel made from biomass. Most U.S. biodiesel is produced from vegetable oils and animal fats. Equipment that uses distillate fuel oil can also use biodiesel. The major sources of feedstock (raw material) for making biodiesel in the United States and their shares of total biodiesel feedstocks in 2018 were

 

Whether trees are burned or whether they decompose naturally, they release the same amount of carbon dioxide into the atmosphere. The idea is that if trees harvested as biomass are replanted as fast as the wood is burned, new trees take up the carbon produced by the combustion, the carbon cycle theoretically remains in balance, and no extra carbon is added to the atmospheric balance sheet—so biomass is arguably considered “carbon neutral.” Since nothing offsets the CO2 that fossil fuel burning produces, replacing fossil fuels with biomass theoretically results in reduced carbon emissions.source

Biomass can reduce carbon dioxide if fast growing crops are grown on otherwise unproductive land; in this case, the regrowth of the plants offsets the carbon produced by the combustion of the crops.

2- Begin to remove from air... removing carbon dioxide from the atmosphere. This is because even if we cut most of our carbon emissions down to zero, emissions from agriculture and air travel would be difficult to eliminate altogether.

Clean Coal' Technologies, Carbon Capture & Sequestration--

Some 27% of primary energy needs are met by coal and 38% of electricity is generated from coal. About 70% of world steel production depends on coal feedstock. Coal is the world's most abundant and widely distributed fossil fuel source. However, each year burning coal produces over 14 billion tonnes of carbon dioxide (CO2), which is released to the atmosphere, most of this being from power generation. Development of new 'clean coal' technologies is attempting to address this problem so that the world's enormous resources of coal can be utilised for future generations without contributing to global warming. Much of the challenge is in commercialising the technology so that coal use would remain economically competitive despite the cost of achieving low, and eventually 'near-zero', emissions. The technologies are both costly and energy-intensive. As many coal-fired power stations approach retirement, their replacement gives much scope for 'cleaner' electricity. Alongside nuclear power and harnessing renewable energy sources, one hope for this is via 'clean coal' technologies, such as carbon capture and sequestration, also called carbon capture and storage (both abbreviated as CCS) or carbon capture, use and storage (CCUS). It involves the geological storage of CO2, typically 2-3 km deep, as a permanent solution. However in its Energy Technology Perspectives 2014 the International Energy Agency (IEA) notes: “CCS is advancing slowly, due to high costs and lack of political and financial commitment.” In its 2016 version of the same report, the IEA reported that there were 17 large-scale CCS projects operating globally.

Carbon Dioxide Removal (CDR) CDR is a must-have to solve the climate crisis

And since carbon dioxide that’s already in the atmosphere can affect climate for hundreds to thousands of years, the IPCC maintains that carbon dioxide removal (CDR) technologies will be critical to get rid of 100 to 1000 gigatonnes of CO2 this century.

from columbia u. https://blogs.ei.columbia.edu/2018/11/27/carbon-dioxide-removal-climate-change/

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