earth

The Earth Itself Is Quieter | Earth Wise

May 15, 2020 By EarthWise Leave a Comment

Our stories often discuss how human activities change the natural environment. With most of us confined to our homes, the lack of human activities is having profound effects on the environment. We are talking about some of these this week.

With about a third of the world’s population sheltering in place, our planet is much quieter these days. It isn’t just our machines, vehicles, and factories that are making less noise. The earth itself is quieter. There has been a reduction in the earth’s seismic vibrations.

According to the journal Nature, various human-powered movements contribute to the persistent vibration of the earth’s crust. Things like engines firing up in factories, trains pulling into stations, and trucks barreling down highways all make contributions to seismic activity. Taken individually, such things are insignificant, but taken together, they produce a background of seismic noise that makes it difficult for seismologists to detect natural signals such as volcanic activity and earthquake aftershocks.

With much human activity on pause during the coronavirus outbreak, seismologists across the globe are seeing significant reductions in background seismic noise levels.

This respite in seismic noise, for as long as it lasts, represents an opportunity for scientists to better study the natural activity in the earth’s crust. Researchers studying the impact of ocean waves to predict volcanic activity and those who triangulate the location of earthquake epicenters may be able to make more sensitive measurements than under normal conditions.

There are very few positive things one can say about the coronavirus crisis, but it is providing opportunities to study and observe aspects of the natural world that are ordinarily drowned out by the bustle of humanity.

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Coronavirus lockdowns across the globe are actually causing the Earth to move less

Photo, posted March 9, 2020, courtesy of Jeremy Segrottvia Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Clouds And Global Warming | Earth Wise

March 9, 2020 By EarthWise Leave a Comment

Recent climate models from multiple organizations project that the amount of warming that doubling atmospheric carbon dioxide would cause would be much more than previously estimated. And one of the significant changes to the models relates to the role of clouds.

Clouds have long been a major uncertainty in climate calculations. Clouds can shade the earth and thereby provide cooling. But clouds can also trap heat. Which effect dominates depends on how reflective the clouds are, how high up they are, and whether it is day or night. The dynamics of clouds are complicated.

If you fly across the ocean, you will see blankets of low clouds extending for hundreds of miles. These marine stratus and stratocumulus clouds predominantly cool the Earth. In fact, they shade roughly a fifth of the oceans and reflect 30-60% of the solar radiation that hits them back into space.

Recent studies indicate that as global temperatures rise, these clouds are likely to become thinner or burn off entirely, leaving more clear skies through which the sun may add another degree Celsius or more to global warming.

The concerns about clouds are part of the larger issue about feedbacks in warming the world. It has long been clear that the greenhouse effect of doubling CO2 levels in the atmosphere would raise global temperature. But there are amplifying feedback effects. Melting large areas of snow and ice reduces reflectivity and allows the land and oceans to absorb more heat. More water vapor entering the atmosphere traps more heat. And now clouds are another concern.

Overall, these effects are leading to climate models predicting much larger global temperature increases, which is a scary prospect for the world.

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Why Clouds Are the Key to New Troubling Projections on Warming

Photo, posted September 10, 2006, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Record Antarctic Temperature | Earth Wise

March 5, 2020 By EarthWise Leave a Comment

It is still early in the year, but extreme weather events are already piling up. January was the warmest month on record globally and there have been many records shattered in Europe and Asia. A number of places in Eastern Europe, including parts of Russia, have seen temperatures 12 to 13 degrees above average.

While the warming of the Arctic has been in the news with increasing frequency, the Antarctic is also seeing rising temperatures and is one of the fastest-warming regions in the world.

On February 6th, Esperanza Base along Antarctica’s Trinity Peninsula measured a temperature of 65 degrees Fahrenheit, which is the highest temperature ever recorded on that continent. This rather balmy temperature narrowly beat out the previous record of 63.5 degrees, which occurred in March of 2015.

This one-time reading is certainly anomalous, and scientists say it is associated with a ridge of high pressure that was lingering over the region for several days. Local wind conditions led to additional warming.

However, the conditions leading to record-breaking high temperatures are not one-time anomalous events. Over the past 50 years, temperatures in the Antarctic have surged by an extraordinary 5 degrees in response to the Earth’s rapidly warming climate. A rise of five degrees in day-to-day weather is no big deal. A five-degree rise in a region’s average temperature is enormous.

About 87% of the glaciers along the west coast of Antarctica’s Trinity Peninsula have retreated over that 50-year period, most of which doing so during just the past 12 years.

Some researchers claim that the new temperature record is an extreme event that doesn’t tell us anything about the changing climate. Many others are convinced that there will be many more high temperature records to follow.

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Antarctica just hit 65 degrees, its warmest temperature ever recorded

Photo, posted February 24, 2019, courtesy of Mike via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

What’s On Nature’s Calendar? | Earth Wise

January 29, 2020 By EarthWise 1 Comment

The Inuit Calendar is based on six seasons defined by weather, ice, animal migration, daylight hours and the night sky. All these variables are in flux according to Harvard Narwhal Biologist Dr. Martin Nweeia. Last August in the high Canadian Arctic, at 72 degrees north latitude, temperatures were at an astounding 70 degrees during the day. In 2018, the same region at the same time of year, experienced one of the coldest August months in 15 years.

Disappearing sea ice in Hudson Bay affects migration patterns of ice-dependent species like narwhal and beluga whales and now allows more shipping traffic which produces more marine noise pollution and the risk of an oil spill. As a natural resource, the Arctic has significant deposits of iron ore, gold, diamonds, phosphate, and bauxite, so cargo shipments are increasing yearly.

The disappearance of caribou herds and altered migrations of other animals have also blurred the seasonal changes. Caribou numbers have decreased by more than half in the last two decades. Narwhal populations are remaining steady but are experiencing migration shifts resulting in their appearance at new locations and their absence from traditional areas. Even the timing of the migration has changed, shifting two weeks later from normal late summer – early fall patterns.

The night sky, which has long had identifiable reference points for Inuit observers, is also changing causing speculation about changes in the magnetic field and a polar shift or flipping of the poles. The earth’s magnetic north has been shifting toward Siberia at an alarming 30 miles each year since 2015. Every million years, it is estimated that the poles flip three times. No one knows if or when it will happen again. That’s a calendar with some unexpected dates.

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–Earth Wise acknowledges script contribution from Dr. Martin Nweeia of Harvard University.

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Migratory Tundra Caribou and Wild Reindeer

Earth’s magnetic field is acting up and geologists don’t know why

Photo, posted June 27, 2014, courtesy of the Bureau of Land Management via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cooling The Earth With A Warmer Arctic | Climate Change | Earth Wise

January 24, 2020 By EarthWise 1 Comment

Researchers are considering a wide range of approaches to mitigate the effects of global climate change. Among these are various strategies of geoengineering, which must be viewed with enormous caution, given the high likelihood of unintended consequences from almost anything we might do.

Researchers at the International Institute for Applied Systems Analysis have investigated potential strategies for cooling the planet in the absence of Arctic sea ice.

The Arctic region is heating up faster than any other place on earth and its sea ice is rapidly disappearing. Estimates are that summer sea ice in the Arctic Ocean will be largely gone within a generation. Arctic ice and snow reflect the sun’s energy into space, which helps to keep the planet cool. What happens if that ice is gone?

The researchers explored the fact that the Arctic Ocean ice actually insulates the Arctic atmosphere from the warmer water under the ice. Without the ice layer, the surface water would actually increase air temperatures by 20 degrees C during the winter. That in turn would increase the heat irradiated into space and thereby cool down the planet.

The Arctic sea ice is in part maintained because the upper regions of the Arctic Ocean have lower salinity than the Atlantic Ocean. This stops Atlantic water from flowing above the cold Arctic waters. So, if we were to somehow deliberately increase the salinity of the Arctic Ocean surface water, warmer, less salty Atlantic Ocean water would flow in, increase the temperature of the Arctic atmosphere, and release heat trapped in the ocean into space.

It all sounds pretty crazy, but the researchers say that given the seriousness of climate change, all options should be considered when dealing with it.

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Could we cool the Earth with an ice-free Arctic?

Photo, posted August 19, 2016, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Another Greenhouse Gas Record

January 7, 2020 By EarthWise Leave a Comment

According to the World Meteorological Organization, levels of heat-trapping greenhouse gases in the atmosphere have reached yet another new record high. Globally averaged concentrations of carbon dioxide reached 407.8 parts per million in 2018, up from 405.5 parts per million in 2017.

The increase year-over-year was similar to that from 2016 to 2017, and remains a little over the average for the last decade. Global CO2 levels crossed the 400 parts per million threshold in 2015.

Concentrations of methane and nitrous oxide also increased by higher amounts than the average for the past decade, based on observations from the Global Atmosphere Watch network with stations all over the globe.

Since 1990, there has been a 43% increase in total radiative forcing – which is the warming effect on the climate from long-lived greenhouse gases. Carbon dioxide accounts for about 80% of this. The report notes that the last time the Earth experienced this high a level of CO2 was 3 to 5 million years ago. At that time, global temperatures were 2 to 3 Celsius degrees higher and sea levels were 30 to 60 feet higher than now.

The report includes data on the isotopic analysis of the CO2 in the atmosphere. CO2 produced by fossil fuel combustion comes from plant material from millions of years ago and does not contain radiocarbon, that is, carbon-14. CO2 from natural sources contains radiocarbon produced by cosmic rays. The increasing CO2 levels in the atmosphere contain decreasing levels of radiocarbon, indicating that the overall increase is largely due to human activities.

Overall, global efforts to date to reduce emissions have not been very successful, and this is borne out by the growing levels of carbon dioxide in the atmosphere.

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Greenhouse gas concentrations in atmosphere reach yet another high

Photo courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why Save Endangered Species?

December 9, 2019 By EarthWise Leave a Comment

One often hears the argument that humans need to save the world’s endangered species in order to save ourselves. Carl Safina, a marine ecologist and award-winning environmental writer, has written a thought-provoking essay that offers the viewpoint that we don’t actually need the wild species of the world but that they need us.

The truth is that human beings have thrived by destroying nature. We have exploited other species when they were useful to us and simply pushed them aside when they weren’t. We drove America’s most abundant bird – the passenger pigeon – to extinction. The most abundant large mammal – the bison – was driven to functional extinction.

In today’s world, people live at high densities in places devoid of wild species and natural beauty. And while we express concern for elephants, gorillas, sperm whales, tigers, and various other species, how would the lives of most of us be affected at all should they vanish entirely? The unfortunate truth is that it would make little difference to our lives.

The only species that are really essential to modern living are actually microbes of decay, a few insect pollinators, and the ocean’s photosynthesizing plankton. Life would go on little changed without most other co-inhabitants of our planet.

Safina argues that our obligation to protect endangered species does not come from our dependence upon them but rather on a moral obligation. Humans consider ourselves to be the most moral species and, as such, we have moral obligations. In this case, it is to protect the beauty and wonder of our world, which is not trivial but in fact is the most profound thing on earth.

Safina has much more to say about this and I strongly recommend reading his essay. You can find the link here.

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The Real Case for Saving Species: We Don’t Need Them, But They Need Us

Photo, posted December 9, 2014, courtesy of Gerry Zambonini via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Ocean Acidification And Mass Extinction

November 26, 2019 By EarthWise Leave a Comment

Since the industrial revolution, the concentration of carbon dioxide in the atmosphere has increased due to the burning of fossil fuels and land use changes. The ocean absorbs about 30% of the CO2 that is released in the atmosphere. As the levels of atmospheric CO2 increase, so do the levels in the ocean.

When CO2 is absorbed by the ocean, a series of chemical reactions occur, resulting in seawater becoming more acidic. Ocean acidification threatens calcifying organisms, such as clams and corals, as well as other marine animals, like fish. When these organisms are at risk, the entire marine ecosystem may also be at risk.

In fact, according to research recently published in the journal Proceedings of the National Academy of Sciences, fossil evidence from 66 million years ago has revealed that ocean acidification can cause the mass extinction of marine life. Researchers analyzed seashells in sediment laid down shortly after a giant meteorite hit earth. This strike wiped out the dinosaurs and 75% of marine species. Chemical analysis of the shells revealed a sharp drop in the PH of the ocean over hundreds of years after the meteorite strike. The meteorite impact vaporized rocks, causing carbonic acid and sulphuric acid to rain down, acidifying the ocean. The strike also resulted in mass die-off of plants on land, increasing atmospheric CO2.

Researchers found that the pH dropped by 0.25 pH units in the 100 to 1,000 years after the meteorite strike. Alarmingly, scientists expect the pH of the ocean to drop by 0.4 pH units by 2100 if our carbon emissions continue as projected.

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Ocean acidification can cause mass extinctions, fossils reveal

Photo, posted March 16, 2017, courtesy of Zachary Martin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The ‘Biggest Ever’ Arctic Expedition

October 3, 2019 By EarthWise Leave a Comment

The Arctic is warming faster than any other region on Earth. In fact, it’s warming at a rate of almost twice the global average. And, since what happens in the Arctic doesn’t stay in the Arctic, the world is already feeling the effects: rising sea levels, changes in climate and precipitation patterns, increasing severe weather events, and so on.

As a result, researchers from more than a dozen countries have launched the biggest and most complex expedition ever attempted in the Arctic. They plan to freeze Germany’s largest research vessel, the Polarstern, into Arctic sea ice, where it will remain trapped for twelve months. The ship will drift with the sea ice as the sea ice drifts. The vessel will serve as a research laboratory, hosting a rotating crew of 300 scientists. The ice, the ocean, the atmosphere, and even the wildlife will all be sampled. This year-long journey will give researchers their closest look at how the polar climate and its fragile ecosystems are changing.

Led by the Alfred Wegener Institute for Polar and Marine Research in Germany, the Multidisciplinary drifting Observatory for the Study of Arctic Climate project (or MOSAiC) is expected to cost about $150 million.

One major goal of MOSAiC is to improve strikingly uncertain climate projections for the Arctic. Climate models disagree on how much more the Arctic will warm as the concentration of greenhouse gases in the atmosphere rises and sea ice shrinks. Some project a 5ºC rise by 2100 relative to the 1986-2005 average. Others predict a 10ºC increase.

Understanding the complex processes occurring in the Arctic is essential for projecting the future impacts of climate change.

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Climate scientists prepare for largest ever Arctic expedition

Climate change: Polarstern leaves for ‘biggest ever’ Arctic expedition

Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

Earth Wise is a production of WAMC Northeast Public Radio.

China And Rare Earth Mining

September 4, 2019 By EarthWise Leave a Comment

Rare earth elements are a crucial part of much of modern technology. Everything from computers to X-ray machines and aircraft engines needs one or more rare earth elements for magnets, lenses, and other functions. The world’s tech giants such as Apple, Huawei, and Tesla depend on suppliers of rare earths.

Rare earth elements are not actually rare, but they are very expensive to extract in ways that are not extremely harmful to the environment. China has been a major source of these elements since its rare earth mining industry took off in the 1990s. The removal of rare earths from the earth’s crust, using a mix of water and chemicals, has caused extensive water and soil pollution.

Today, concrete leaching ponds and plastic-lined wastewater pools dot the hills of Southeast China. Large wastewater ponds sit uncovered and open to the elements in many places. Landslides or barrier failures can spill contaminated contents into waterways or groundwater.

Local and federal officials in China have started to shut down illegal and small-scale rare earth mining operations and have embarked on a cleanup of polluted sites. The rare earth mining cleanup operation is part of wider efforts across China to address severe problems of water, air and soil pollution.

China’s Ministry of Industry and Information Technology estimated that the cleanup bill for southern Jiangxi Province could amount to more than $5 billion. Many environmental experts and local officials say that the cost of the cleanup should not be shouldered by the Chinese government alone, but also by the rare earth industry and the global companies and consumers that benefit from rare earth technology. As rare earth mining efforts start up elsewhere around the world, it is important not to repeat the mistakes made in China.

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China Wrestles with the Toxic Aftermath of Rare Earth Mining

Photo, posted April 21, 2019, courtesy of John Beans via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Return Of An Old Threat

July 3, 2019 By EarthWise Leave a Comment

The 1987 signing of the Montreal Protocol was one of the biggest victories for global environmental stewardship. The 197 signatory nations banded together to address a planetary emergency: the depletion of the ozone layer in the upper atmosphere resulting from the use of chlorofluorocarbons or CFCs.

Over the years, there were celebratory headlines like “The Earth’s Ozone Hole is Shrinking” and “Without the Ozone Treaty, You’d Get Sunburned in 5 Minutes”. And indeed, the hole in the ozone layer has shrunk over time.

However, the presence of CFCs in the atmosphere is continually monitored and studies in recent years reported new emissions of about 13,000 tons of CFC-11 a year from somewhere in eastern Asia starting in 2012. That was two years after the 2010 date for ending all CFC production under the terms of the Montreal Protocol.

A new study published in Nature has pinned down the source of more than half of the new CFC emissions to the provinces of Shandong and Hebei on the northeastern coast of China. The bulk of these emissions are believed to come from small factories using the chemical to manufacture foam insulation used in refrigerators and buildings.

The Chinese government has already shut down two manufacturing locations, but undercover agents have found that 18 out of 21 manufacturers in the region are using the banned substance. They appear to be quite adept at circumventing enforcement.

The new emissions aren’t large enough so far to be catastrophic, but the Chinese government needs to crack down on this illegal activity. It is difficult to stop because these are small companies operating in meth lab-like facilities. Saving the earth’s atmosphere from ourselves is a tricky business.

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How an Illicit Chemical Is Jeopardizing Recovery of the Ozone Layer

Photo, posted July 28, 2012, courtesy of Beth Scupham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Economic Inequality

June 3, 2019 By EarthWise 1 Comment

A new study by Stanford University looked at the effects of climate change on global economic inequality. The study found that the gap between the economic output of the world’s richest and poorest countries is larger today than it would have been without global warming.

The warming climate has enriched cooler countries like Norway and Sweden while dragging down economic growth in warm countries such as India and Nigeria. The results of the study showed that most of the poorest countries on Earth are considerably poorer than they would have been in the absence of rising temperatures. At the same time, the majority of rich countries are richer than they would have otherwise been.

Detailed analysis of 50 years of annual temperature and GDP measurements for 165 countries demonstrated that growth during warmer than average years has accelerated in cool nations and slowed in warm nations. Historical data clearly show that crops are more productive, people are healthier, and they are more productive at work when temperatures are neither too hot nor too cold. That means that in cold countries, a little bit of warming can help but the opposite is true in places that are already hot.

For most counties, whether global warming has helped or hurt economic growth is pretty certain. Tropical countries in particular tend to have temperatures far outside the ideal for economic growth and they are already among the poorest countries. It is less clear how warming has influenced growth in countries in the middle latitudes, such as here in the United States. Some of the largest economies are near the perfect temperature for economic output but continued warming in the future is likely to push them away from the temperature optimum.

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Climate change has worsened global economic inequality

Photo, posted November 1, 2011, courtesy of CIAT via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Antarctic Warming

April 23, 2019 By EarthWise Leave a Comment

East Antarctica is the coldest place on Earth. It makes up two-thirds of the continent, is home to the South Pole, and has vast ice sheets that have been around for tens of millions of years and are nearly three miles thick in places. Temperatures there hover around 67 degrees below zero. In 2010, a few spots on East Antarctica’s polar plateau reached a record-breaking 144 degrees below zero.

But almost unbelievably, parts of the East Antarctic seem to be melting.

Scientists are seeing worrying signs of ice loss in the East Antarctic. Glaciers are starting to move more quickly and are dumping their ice into the Southern Ocean. Satellite images show the fast-moving ice. The biggest glacier – the Totten Glacier – alone contains enough ice to raise global sea levels by over 12 feet.

The Antarctic as a whole contains about 90% of the planet’s ice. In theory, if it all melted, it would raise global sea levels by an average of 200 feet.

The growing concerns about eastern Antarctica are not that its interior plateau will soon start to melt. It is still extremely cold there and should stay that way for a long time. But its edges, which are in contact with warming ocean waters, are the real worry. As the region’s ice shelves, which float atop the Southern Ocean, erode, the vast glaciers behind them could rapidly accelerate their slide into the sea.

Today, satellites show huge glaciers moving rapidly toward the coast, with wide rivers of ice sometimes moving several miles a year. In the face of rapid change and limited data, it is difficult to predict what the Antarctic will do in the future. But it doesn’t look good.

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Polar Warning: Even Antarctica’s Coldest Region Is Starting to Melt

Photo, posted January 3, 2013, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Humans And Vertebrate Mortality

April 9, 2019 By EarthWise Leave a Comment

According to a new study, more than one-quarter of the planet’s land vertebrates die because of humans. This is a “disproportionately huge effect” on the other land vertebrates that share planet’s surface with us.

Researchers from the SUNY College of Environmental Science and Forestry and the U.S. Department of Agriculture reviewed 1,114 published studies in which nearly 43,000 animals had perished. Their study, which was recently published in the journal Global Ecology and Biogeography, found that 28% of the animals’ deaths were directly attributable to humans. The other 72% died from natural sources.

Mammals, birds, reptiles, and amphibians that died between 1970 and 2018 in the Americas, Asia, Africa, Europe, and Oceania were the foundation of the study. All of these vertebrates had been either collared or tagged as part of other research projects.

The researchers point out that humans are only one among more than 35,000 species of terrestrial vertebrates globally. The fact that humans are responsible for more than one-quarter of their deaths illustrates the profound magnitude of the problem. And that statistic is just the direct causes. According to the researchers, when urban growth and other land use changes that erode habitat are considered, the human impact is likely even greater.

The study found that the impact of humans across all the different species was not equal. In fact, larger animals were more likely to be killed by humans than smaller animals. Adult animals were more likely to be killed by humans than juveniles.

The researchers conclude that humans are such a major contributor to terrestrial vertebrate mortality that they could potentially impact both evolutionary processes and ecosystem functioning.

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On the land, one-quarter of vertebrates die because of humans

Photo, posted March 6, 2019, courtesy of USFWS Midwest Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Natural Climate Solutions Are Not Enough

April 1, 2019 By EarthWise Leave a Comment

A new policy perspective published in Science by researchers at seven prestigious institutions looked at the role of natural science solutions in stabilizing the Earth’s climate for people and ecosystems. While they asserted that it is imperative to ramp up natural climate solutions, they also concluded that natural solutions alone will not be sufficient.

Natural science solutions include such things as enhancing carbon sinks from forests, agriculture and other lands. Doing these things are very beneficial in their own right as they lead to improved forests, croplands, grazing lands, and wetlands.

However, these things will not be enough to meet the goals of the Paris Climate Agreement and must be combined with rapid efforts to decrease emissions from the energy and industrial sectors. Among their various findings, the researchers warn that a ten-year delay in emissions reductions from these sectors could completely negate any potential benefits of natural climate solutions.

As has become increasingly clear, there is not an either-or situation with regard to the actions that need to be taken with respect to climate change.

Maximizing natural climate solutions and reducing emissions from the energy and industrial sectors will provide broad benefits beyond climate change mitigation. Doing these things will improve forests and habitats, reduce the risk of wildfires, and decrease air and water pollution thereby improving human health and well-being.

Of course, to reduce cumulative emissions and put a cap on the warming of the planet, there will need to be policy mechanisms and incentives in place that support both natural climate solutions and increasing mitigation efforts across the energy and industrial sectors.

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Natural Climate Solutions Are Not Enough

Photo, posted February 11, 2012, courtesy of Joao Andre O. Dias via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Glaciers And Water Supply

March 25, 2019 By EarthWise Leave a Comment

The world has roughly 150,000 glaciers covering about 200,000 square miles of the earth’s surface. Over the last 40 years they’ve lost the equivalent of a layer of ice 70 feet thick. Most of them are getting shorter as well. Some have shrunk to nothing; many smaller glaciers in places like the Rockies and the Andes have disappeared entirely.

Glaciers represent the snows of centuries, compressed over time to form flowing rivers of ice. They always change over time, accumulating snow in winter and losing ice to melting in summer. But in recent times, the warming climate has allowed the melting to outpace the accumulation.

Much of the discussion about the retreating glaciers relates to sea level rise, catastrophic floods, debris flow, and the effects on rivers and ecosystems.

But in some places, the biggest impact of the loss of glaciers is on the supply of water for people and agriculture. In Kazakhstan, Almaty, the country’s largest city depends on glacier-fed rivers for drinking water for its 2 million people and for irrigation water for crops. All across the Tibetan Plateau and the Himalayan and Karakmoram mountain ranges, hundreds of millions of people rely on glacier-fed rivers for their water supplies.

A melting glacier can at first increase stream flow but eventually reaches a tipping point and meltwater begins to taper. In the short term, the melting glaciers may provide increased amounts of water coming down from the mountains, but eventually the flow in the rivers will begin to decline and populations will face a crisis.

It will be essential for people in many places to carefully plan for their future water needs in a changing world.

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Glaciers Are Retreating. Millions Rely on Their Water.

Photo, posted September 16, 2011, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Speed Breeding Of Crops

January 4, 2019 By EarthWise Leave a Comment

A technique pioneered by NASA for the purpose of growing plants extra-terrestrially is now being applied here on earth to fast-track improvements in a range of crops. The technique, known as speed breeding, has been adapted for use by British and Australian researchers on a scale ranging from vast greenhouses to desktop growth chambers.

Speed breeding uses enhanced LED lighting and day-long regimes of up to 22 hours to optimize photosynthesis and promote rapid growth of crops. By speeding up the breeding cycle of plants,it is possible, for example, to grow six generations of wheat in a year compared with two generations using traditional breeding methods.

With shortened breeding cycles, genetic improvements such as yield gain, disease resistance and climate resistance can be fast-tracked in crops such as wheat, barley, chickpeas, various Brassica species, oil seed rape and peas.

The ability to do this in compact desktop chambers permits cutting-edge research to be performed inexpensively before being scaled up to large greenhouses.

Crop development is an increasingly important activity and speed breeding is increasingly attractive in light of the opposition in some quarters to modern gene-editing techniques to create GMO crops. Speed breeding allows crop improvements via anon-GMO route.

The new technique is already being applied in Australia, which is experiencing one of the worst droughts on record. It is being used to rapidly cycle genetic improvements to make crops more drought resilient.

Generation time in most plant species is a major bottleneck in applied research programs and breeding. Speed breeding can greatly reduce this bottleneck, allowing scientists to respond more quickly to emerging diseases, the changing climate and increased demand for specific plant traits.

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