Causes of global warming
Temperature anomaly for June 2012 relative to the average from 1951-1980 according to NASA.
By Jeremy Hance
Global warming, also known as climate change, is an ongoing global environmental crisis in which the Earth's temperature is steadily rising. Global temperatures have risen about 0.8 degrees Celsius (1.4 degrees Fahrenheit) since the early Twentieth Century and are expected to continue to rise. The fact that the Earth is warming is unequivocal, according to the United Nations Intergovernmental Panel on Climate Change (IPCC).
But what is causing the Earth to warm?
The quick answer: humans burning fossil fuels. The longer answer: the scientific consensus is that greenhouse gas emissions, especially of carbon, are causing the majority of the current temperature rise. The bulk of these emissions come from burning fossil fuels such as coal, oil, and natural gas. Other causes include deforestation and land use changes, which releases sequestered carbon back into the atmosphere, and industrialized agriculture. Since the Industrial Revolution, humans have increased the concentration of carbon in the atmosphere by about a third. Greenhouse gases, like carbon, trap heat in the Earth's atmosphere, instead of allowing it to escape.
In 2007 the IPCC found that there was over a 90 percent certainty that human activity was directly responsible for current global warming. Five years later many scientists say that certainty has only increased.
A small minority of scientists disagree that greenhouse gas emissions are causing the Earth to warm. However, are often not experts on climate. Various other theories for current warming, such as solar activity or faulty instrumentation, have been examined in-depth and found to have weaker correlation than carbon emissions.
Unless tackled, climate change is expected to raise sea levels, melt sea ice and glaciers, worsen droughts and floods, increase wildfires, substantially alter global agriculture, contribute to widespread species extinctions, and possibly increase conflict around the world.
Recent news on global warming
Conserving top predators results in less CO2 in the air
(06/19/2013) What does a wolf in Yellowstone National Park have in common with an ambush spider on a meadow in Connecticut? Both are predators and thus eat herbivores, such as elk (in the case of wolves) and grasshoppers (in the case of spiders). Elk and grasshoppers also have more in common than you probably imagine: they both consume large quantities of plant matter. While scientists have long-known that predators lead to carbon storage by reducing herbivore populations, a new study reveals a novel way in which top predators cause an ecosystem to store more carbon.
Seabirds face big problems as sea levels rise
(06/19/2013) Migratory shorebird populations are at great risk from rising sea levels due to global climate change, warns a recent paper in Proceedings of the Royal Society B. These birds play an important role in the distribution of nutrients within wetland and coastal ecosystems, and their loss could have unknown consequences for the rest of the world.
Warming world hits fig wasps and figs
(06/19/2013) Recent experiments concerning hugely-important fig plants (Ficus) and their relationship with small, short-lived fig wasps suggest dire potential consequences due to human induced climate change, finds a study published in the journal Biology Letters. The researchers collected four species of adult female fig wasps from the lowland tropical forests of Singapore to test their tolerance to gradually increased temperatures.
Should zoos educate the public about climate change?
(06/18/2013) Zoos are usually thought of as entertainment destinations. As a place to take the kids on a nice afternoon, they are sometimes perceived to lack the educational heft of an art museum or a theatre. However, over the past few decades many of the world's best zoos and aquariums have also worked to educate their visitors about conservation issues, in addition to funding and supporting programs in the field to save the ever-growing number of imperiled species. But as threats to the world's species mount—including climate change—many are beginning to ask what, if anything, zoos and aquariums should do to address the global environmental crisis.
Poisonous jellyfish on the rise in the Mediterranean
(06/11/2013) Scientists across the Mediterranean say a surge in the number of jellyfish this year threatens not just the biodiversity of one of the world's most overfished seas but also the health of tens of thousands of summer tourists.
NASA: 3% of Amazon rainforest burned between 1999-2010
(06/08/2013) 33,000 square miles (85,500 square kilometers) or 2.8 percent of the Amazon rainforest burned between 1999-2010 finds new NASA-led research that measured the extent of fires that smolder under the forest canopy.
Southern U.S. logging soars to meet foreign biofuel demand
(06/06/2013) In order to meet the European Union's goal of 20% renewables by 2020, some European utility companies are moving away from coal and replacing it with wood pellet fuel. The idea is simple: trees will regrow and recapture the carbon released in the burning of wood pellets, making the process supposedly carbon-neutral. But just like other simple ideas, it misses out important details that can turn it on its head.
Rainforests will survive extreme global warming, argues study
(06/02/2013) Rainforests in South America have endured three previous extreme global warming events in the past, suggesting they will survive a projected 2-6 degree rise in temperatures over the coming century, reports a study published in the Annual Review of Earth and Planetary Science. The research, published by Carlos Jaramillo and Andrés Cárdenas of the Smithsonian Tropical Research Institute (STRI) in Panama, reviewed some 3,800 published estimates of temperature over the past 120 million years and compared them to the existence of tropical plants in the fossil record.
Millennium Development Goals falling short on environmental ambitions
(05/30/2013) This week in New York City, the 27 members of the high-level panel of eminent persons appointed by the U.N. Secretary General will deliver a report providing recommendations on the post-2015 development agenda. This is a critical opportunity to address the inadequacies of the Millennium Development Goals (MDGs) and to chart a new course for sustainable development.
Earth likely to warm between 2 and 6 degrees Celsius this century
(05/30/2013) A new study by Australian scientists projects that the world will likely warm between 2 and 6 degrees Celsius (3.6 to 10.8 degrees Fahrenheit) from pre-industrial levels by 2100. The study published in Nature Climate Change finds that exceeding the 2-degree threshold is very likely under business-as-usual emissions scenarios even as scientists have long warned that passing the 2-degree mark would lead to catastrophic climate change.
Water crisis widening: 4.5 billion people live near 'impaired water sources'
(05/28/2013) The majority of the 9 billion people on Earth will live with severe pressure on fresh water within the space of two generations as climate change, pollution and over-use of resources take their toll, 500 scientists have warned.
Over 500 scientists warn we 'are causing alarming levels of harm to our planet'
(05/27/2013) A new consensus statement by 520 scientists from around the world warns that global environmental harm is putting at risk the happiness and well-being of this and future generations.
Plants re-grow after five centuries under the ice
(05/27/2013) While monitoring the retreat of the Teardrop Glacier in the Canadian Arctic, scientists have found that recently unfrozen plants, some of which had been under ice since the reign of Henry VIII, were capable of new growth.
Indonesia's largest coal plant will be built despite protests, minister says
(05/26/2013) Indonesia will go ahead with construction of what is set to be its largest coal-fired power plant in Batang, Central Java next year, a senior government official has said, downplaying opposition from environmental groups and the local community. Developers have struggled to acquire the approximately 200 hectares of land needed for the planned PLTU Batang plant, which would have a 2000 megawatt (MW) capacity. Residents of five villages have protested the project, with some refusing to release their land on fears of potential environmental damage to the area. Environmental groups also oppose the plant, saying it overlaps with a marine protected area and runs counter to President Susilo Bambang Yudhoyono’s commitment to reduce carbon emissions.
China to begin cutting carbon emissions one city at a time
(05/23/2013) China has unveiled details of its first pilot carbon-trading program, which will begin next month in the southern city of Shenzhen. The trading scheme will cover 638 companies responsible for 38% of the city's total emissions, the Shenzhen branch of the powerful National Development and Reform Commission (NDRC) announced on Wednesday. The scheme will eventually expand to include transportation, manufacturing and construction companies.
Biosphere conservation: monumental action is critical to avert global environmental crisis
(05/20/2013) Human-caused changes to our biosphere—the global total of the world's ecosystems—are now so great and alarmingly rapid that human lives and societies undoubtedly face epic challenges in the near future as our biosphere deteriorates, planetary boundaries are reached, and tipping points exceeded. We may survive, we may painfully adapt, but it is a fair bet that grave hardship, loss, and sacrifice lay ahead. The nature and extent of impacts among human populations hinges on how successfully we respond to the biosphere crisis with extraordinary leadership, balanced solutions applied at global scales, and unprecedented cooperation—or not.
Scientists have reached an overwhelming consensus on human-caused climate change
(05/16/2013) Despite outsized media and political attention to climate change deniers, climate scientists long ago reached a consensus that not only is climate change occurring, but it's largely due to human actions. A new study in Environmental Research Letters further strengthens this consensus: looking at 4,000 peer-reviewed papers researchers found that 97 percent of them supported anthropogenic (i.e. human caused) global warming. Climate change denialists, many of them linked to fossil fuel industries, have tried for years—and often successfully—to undercut action on mitigating climate change through carefully crafted misinformation campaigns.
Canadian government drops over $16 million on advertising its tar sands
(05/16/2013) The Canadian government has nearly doubled its advertising spending to promote the Alberta tar sands in an aggressive new lobbying push ahead of Thursday's visit to New York by the prime minister, Stephen Harper. The Harper government has increased its advertising spending on the Alberta tar sands to $16.5m from $9m a year ago.
Pacific islanders are the 'victims of industrial countries unable to control their carbon dioxide emissions'
(05/15/2013) With islands and atolls scattered across the ocean, the small Pacific island states are among those most exposed to the effects of global warming: increasing acidity and rising sea level, more frequent natural disasters and damage to coral reefs. These micro-states, home to about 10 million people, are already paying for the environmental irresponsibility of the great powers.
Eat insects to mitigate deforestation and climate change
(05/14/2013) A new 200-page-report by the UN Food and Agriculture Organization (FAO) urges human society to utilize an often-ignored, protein-rich, and ubiquitous food source: insects. While many in the industrialized west might turn up their noses at the idea of eating insects, already around 2 billion people worldwide eat over 1,900 species of insect, according to the FAO. Expanding insect-eating, the authors argue, may be one way to combat rising food needs, environmental degradation, and climate change.