The polar regions of the Earth are known as areas of harsh weather extremes. However, in the current warming climate, we are seeing record breaking temperature spikes, rapid sea ice loss and increased rainfall compared to snow accumulation in Arctic regions, that seemingly far surpass weather variations of the recent past. In fact, a recently published study has determined that the Arctic is shifting to a new and different climate, one characterised less by ice and snow and more by open water and rain.

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The study, published in Nature Climate Change in September, utilised five climate models to investigate the potential emergence of a new Arctic climate in three different factors across ocean and land: sea ice, air temperature and precipitation phase, i.e. snow vs rain. By identifying the emergence of a new climate, which has previously been seen in terrestrial systems and subpolar latitudes, it is possible to gain insight into future weather extremes, which have great importance for both the environment and the people who live there. The three factors investigated by this study are not only important indicators of a new climate but are also highly interconnected. 

Arctic temperatures are rising at a rate of nearly twice the global average due to an effect known as Arctic amplification. Arctic amplification is largely attributed to the loss of sea ice as the ice plays two key roles in regulating near-surface air temperature. First, it provides an albedo feedback. Simply put, the light colour of the sea ice, compared to the Arctic ocean beneath it, reflects a majority of incoming solar radiation back into the atmosphere, preventing it from being absorbed and warming the environment. Second, its thickness provides insulation between the warmer ocean below and the cooler air above. Therefore, as temperatures rise and sea ice melts, more of the Arctic ocean will be exposed meaning more solar radiation will be absorbed by the darker ocean, causing the ocean temperatures to rise. Further, with sea ice thinning, or being lost completely, insulation provided by the sea ice decreases, resulting in increased air temperature due to its closer proximity to a warmer ocean. As air temperatures rise, the phase of precipitation changes in concert leading to rainfall replacing snowfall and an extension of the rainy season. 

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In order to classify the emergence of a new climate for any of these three factors, researchers needed to characterise twentieth century climate and compare it to observed and simulated twenty-first century climate to determine if the extreme changes occurring are a result of climate change, and thus a new climate, or if they fall within natural internal variability. While the problem seems straightforward, coming to a solution is anything but. Observational data in the Arctic is sparse and is sourced largely from the modern satellite era, beginning in 1979, which itself was a period of drastic change in the Arctic. Further, limited records also suggest a period of warming and sea ice loss during the 1950’s, making it extremely difficult to characterise twentieth century Arctic climate. Yet, using a multi-model, the study was able to robustly characterise the past Arctic climate and simulate the twenty-first century climate using the representative concentration pathway (RCP) 8.5 scenario put forward by the Intergovernmental Panel on Climate Change, commonly referred to as the ‘worst case scenario’ or ‘business as usual’ projection for greenhouse gas concentration in the atmosphere. 

The study concludes that the Arctic is already transitioning from a cryosphere-dominated system, with the average extent of sea ice in September, the time of year when sea ice extent is at its minimum, having decreased by 31% from the beginning of the satellite era (1979 – 1988). Further, they report a new Arctic climate of sea ice as having already emerged, beginning in the late twentieth century to the beginning of this century. 

Using the RCP 8.5 scenario, all five models simulate a completely ice-free summer by 2100 with air temperatures exceeding those of lower latitudes. Daily fall-winter temperatures are also projected to increase by 16 – 28 °C for most of the Arctic Ocean. Lastly, rainfall will replace snowfall with an extension of the rainy season by 2 – 4 months. This new Arctic climate and the predicted changes set to accompany it will take a heavy toll on both the ecosystem and people who live and rely on these Arctic environments. 

It is important to remember, however, that these simulations are based on the ‘worst case scenario’ of greenhouse gas concentrations, with the study noting that a reduction in greenhouse gases could postpone or even completely prevent the emergence of future new Arctic climates. This is important as the study estimates that a new climate of air temperature and precipitation phase change will emerge in the first to middle half of this century and in the middle half of this century respectively.  It is therefore still feasible that this future does not need to become our new reality. With efforts and plans made now, we can all decrease our carbon footprint and ensure that the ‘worst case scenario’ is not the path we choose to follow. 

Featured image by: Flickr

The post The Arctic is Shifting to a New Climate: What Does This Mean? appeared first on Earth.Org.

With the current state of our climate, many people are assessing their personal carbon footprint and impact on climate change. For some, this assessment extends to death, more specifically their burial.  While conventional burials including coffins, tombstones and extensive methods of body preservation are still fairly common, their toll on the environment is heavy. As the crisis accelerates, how can we ensure that our carbon footprint ends with us? Recomposition could be one such solution. 

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In the US alone, roughly 22 500 cemeteries across the country bury roughly 827 060 gallons of embalming fluid, commonly containing formaldehyde, 104 000 tons of steel, 2 700 tons of copper and bronze, 30 million board feet of hardwood and 1.6 million tons of reinforced concrete. Additionally, countries have another problem: they are running out of space. In fact, a survey conducted in 2013 in the UK reported nearly half of England’s cemeteries could reach capacity within the next 20 years. While cremation rates are on the rise in the UK and US, providing a solution to the real estate problem, it creates a potentially larger problem for the climate. Crematoriums produce on average of 534.6 pounds of CO2 per person, totalling roughly 360 000 metric tons of CO2 emissions each year in the US alone, while the more traditional cremation method of a wood pyre, commonly used in Asia, results in the felling of over 50 million trees every year and contributes to air and river pollution.  

As the need to be environmentally conscious is more dire than ever, alternate solutions to these common burial practices, such as recomposition, have developed. Aquamation is an environmentally friendly alternative to cremation that involves the dissolution of remains in a water-alkali solution, resulting in a nutrient rich liquid that can be either disposed of via normal drainage or given to farmland as a fertiliser. This process produces zero greenhouse gas emissions and has a tenth of the carbon footprint of a standard cremation. For those who prefer to be buried, natural or green burials have become an appealing choice, as they are similar to common burials except that the remains are buried in a manner which does not prevent natural decomposition. This means that the body is buried in either a biodegradable coffin or shroud, no chemicals such as embalming fluid are used, a shallow grave is dug to permit microbial activity and no permanent grave marking is used. While natural and green burials are a step in the right direction, one aspect unaccounted for is the release of toxins built up in the body at the time of burial, leading to their release during decomposition.  

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The Center for Disease Control in the US reports that a person can have up to 219 toxic chemicals in their body, including tobacco residue, pesticides, fungicides, heavy metals and preservatives. They also reported Bisphenol-A (BPA), a synthetic estrogen and plastic hardener, in 93% of adults over 6 years old. Thus, in conventional burials, cremation and even green burials, these toxins are released back into the environment upon decomposition or burning. Some companies, such as Recompose and Coeio, are currently working to address this problem. Coeio’s process is similar to a traditional green burial in the sense that the bodies are buried in shallow graves with no preservation chemicals or permanent grave markers. However, they have taken it a step further to develop an Infinity Burial Suit and Infinity Burial Shroud, which harness the power of mushrooms and microbiology to neutralise toxins found in the body, aid decomposition and transfer nutrients to plant life. Both products are made from completely biodegradable organic cotton, developed by the zero-waste fashion designer Daniel Silverstein, and have a uniquely developed biomix, containing mushroom mycelium and microbes, built into the fabric. As the body naturally decomposes, the mushrooms and microbes work to break down and neutralise toxins as well as make the nutrients bioavailable to surrounding plant life. Coeio’s products are currently available for purchase and can be obtained well in advance of the burial and even death as they can be safely stored in a cool, dark place until required.  

Recompose, a Washington-based company, has similar principles as Coeio, but executes them in a very different way. Recompose will receive the body at their facility where their staff will lay the body in a cradle surrounded by wood chips, alfalfa and straw. The cradle is then placed within the Recompose vessel where it is covered in more plant material and the process of natural organic reduction (NOR) occurs. NOR uses thermophilic, heat-loving microbes and bacteria to break down organic material and neutralise toxins and pathogens. By controlling the ratio of carbon, nitrogen, oxygen and moisture in the vessel, Recompose can achieve NOR in typically 30 days, resulting in the complete breakdown of the entire body, including bones and teeth, into clean, nutrient-rich soil. Each body produces one cubic yard of soil, about the volume of a pickup truck bed, and can save the release of roughly 1 metric ton of carbon dioxide. Further, any non-organic material in the body, such as artificial limbs, metal fillings or pacemakers will be recycled when possible. The soil produced can be collected by the family to be used to nourish trees or plants, however Recompose also offers an opportunity to donate some or all of the soil to the Bells Mountain conservation forest, where it will assist with revitalisation of clear-cut fields, wetlands and vulnerable wildlife. As of this year, Washington State became the first state in the US to legalise NOR, allowing Recompose to begin accepting bodies in November 2020. 

Death care is an extremely personal decision for the individual and family, and there is no right or wrong choice when making this decision. As the climate crisis advances and society begins to shift to a more sustainable and low impact lifestyle, we are becoming more informed and calculated about the choices we make in life. Companies such as Recompose and Coeio are taking that mentality one step further in assisting to make death as much a part of the solution as the choices we make today, all in an effort to leave the Earth better than we found it.

Featured image by: Flickr 

The post Recomposition: A New Life After Death appeared first on Earth.Org.

71% of Earth’s surface is covered in water, yet more is known about the surface of the moon than the entirety of the oceans. Reliance on the world’s oceans feeds into almost every aspect of human lives, including daily weather, food, the movement of goods and most importantly, the oxygen that humans breathe. Blooms of oceanic diatoms, small single-celled algae, produce up to 80% of the world’s oxygen, but are sensitive to changing ocean conditions. The depletion of oxygen from the ocean is called deoxygenation, but what exactly does this mean?

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The health of our oceans has been steadily declining over the past century due to pollution, overfishing and a warming climate. An increase in global temperatures has led to ocean temperatures responding in concert. Global surface sea level temperatures have been increasing at an average rate of 0.13 °F per decade from 1901 to 2015. While this may not seem like a large change, the warming of ocean temperatures carries serious consequences for the planet. Warm water is unable to hold as much gas as cold water, resulting in lower oxygen levels in the ocean- deoxygenation- and reduced uptake of carbon dioxide from the atmosphere.  

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Effects of Ocean Deoxygenation

At present, the ocean is a net sink for carbon dioxide, meaning it absorbs more carbon dioxide than it produces, helping to counterbalance atmospheric greenhouse gas levels. In fact, the Earth’s oceans have absorbed around one third of the carbon dioxide produced by humans since the beginning of the Industrial Revolution. Yet, as surface waters warm they become more buoyant, preventing them from mixing with cold water found deeper in the ocean. This impacts the amount of carbon dioxide the ocean is able to absorb from the atmosphere as the mixing of surface and deeper waters allows the newly-absorbed carbon to sink and be replaced by cooler bottom water, which can absorb more carbon dioxide. As this mixing slows, uptake of atmospheric carbon dioxide will decrease as the warm, gas-saturated surface water will be unable to continue absorbing carbon dioxide at the same rate, leading to higher concentrations in the atmosphere and increased oceanic warming.

In addition to warming ocean temperatures, nutrient pollution of coastal environments through fertiliser run-off, sewage, animal waste and nitrogen deposition from the burning of fossil fuels promotes excessive algal growth in ocean surface water. After the algae die and their cells sink, bacteria breaks down the cells for energy in a process that consumes oxygen and produces carbon dioxide, leading to a further reduction in water oxygen levels and an increase in carbon dioxide. This process, known as eutrophication, in combination with warming ocean temperatures, results in an overall decrease in oceanic oxygen levels and in some cases the production of hypoxic zones, or ‘Dead Zones’: areas where dissolved oxygen levels are too low to support life. These Dead Zones impact on food web structures, biodiversity and potential fish yields.  

Further, low-oxygen regions have the potential to release nitrous oxide and methane, two powerful greenhouse gasses, through their production in deoxygenated deep ocean waters that may then reach surface waters and be released to the atmosphere.  The Gulf of Oman, the Baltic Sea and the Gulf of Mexico are the three largest recurring Dead Zones in the world, with the Gulf of Oman totalling an area larger than that of Scotland, while another study has reported a growth of 55 000 km² of the Baltic Sea Dead Zone over the last century. 

A new report by the International Union for Conservation of Nature (IUCN) reports an overall 2% decline in the world’s ocean oxygen levels since the 1950s, with a further predicted fall of 3-4% by 2100. This ocean deoxygenation will have serious consequences for biodiversity, commercial fishing and tourism in coastal regions. Large marine animals that require considerable amounts of oxygen, or hypoxia-sensitive animals, such as tuna, swordfish, and most other fish we eat, will be forced to surface waters or other areas of the ocean in search of higher oxygen levels, which may lead either to their overfishing or a severe disruption to commercial fishing. In contrast, hypoxia-tolerant species, such as microbes, jelly fish and some squid, will likely dominate most other species, leading to unsafe water and beach qualities, consequently influencing tourism worldwide. 

Ocean Deoxygenation: Everyone’s Problem

Ocean warming and deoxygenation is a problem that will have repercussions for everyone on the planet. Actions need to be implemented now for the ocean to have a chance to recover. Carbon dioxide emissions must be urgently cut in order to mitigate ocean warming, as scientists predict recovery rates on the time scale of centuries under ‘business as usual’ emissions. Regulations to reduce nutrient run-off from both agriculture and sewage also need to be implemented to decrease the over-enrichment of coastal waters which leads to eutrophication.  

Featured image by: Peta Hopkins

The post Deoxygenation: What To Expect From Our Future Oceans appeared first on Earth.Org.

Glaciers and ice sheets currently cover around 10% of the Earth’s surface and are vital for shaping its physical landscape, reflecting intense solar radiation and supplying many people around the world with freshwater. Until recently, however, one characteristic of this environment has remained largely overlooked. What are algae blooms and how are they affecting the landscape?

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Algae blooms living on the surface of the south-west coast of the Greenland Ice Sheet (GrIS) are causing darkening of the sheet, leading to increased rates of melting not currently being incorporated into melt rate models.

Glaciers and ice sheets are extremely dynamic ecosystems, capable of hosting abundant and diverse microbial life. Areas of the Earth in which water is found in a solid, frozen form are now termed the Cryosphere, which is considered one of the Earth’s five biospheres. Due to extreme and harsh conditions, particularly in the Arctic and Antarctic, microbial abundance, diversity and activity in these environments have been given little global prominence.  

Microbial life has now been documented in most areas of glaciers and ice sheets, including at the bedrock-ice interface, on the ice surface and inside the ice itself. Most initial research focused on microbial communities living at the bedrock-ice interface due to their influence on nutrient export to fjord and ocean environments. Surface ice environments, comprised of snow packs, bare ice, lakes and streams, have recently begun to take centre stage as microbial communities thriving in these habitats have drastically changed the physical appearance of glaciers and ice sheets worldwide. Areas of high microbial abundance and activity, known as cryoconite holes, have quickly become the primary focus of attention in surface ice environments. Cryoconite is a dark substance now found on most glacier and ice sheet surfaces worldwide, with areas of high abundance described as having the appearance of swiss cheese. 

It wasn’t until 2012 that scientists discovered a habitat other than cryoconite holes: the ice surface itself. A study of the GrIS found that the top two centimetres of the ice surface hosts abundant microbial life, dominated mainly by Streptophyta algae, now termed glacier algae.  

Prior to this finding, satellite imagery revealed a significant annual darkening occurring since 2000 on the surface of the GrIS, on an area about 20-30 km inland and 50 km wide, now known as the ‘Dark Zone’. Many scientists initially attributed this darkening to common light-absorbing particles such as atmospheric dust, black carbon from the burning of fossil fuels, dust melting out of ancient ice and even cryoconite. Cryoconite holes typically cover only 3-6% of the whole GrIS, whereas glacier algae appear to bloom wherever bare ice is present, therefore covering far greater areas.  In fact, a study reported an abundance of up to 85 thousand glacier algae cells per milliliter of melted surface ice collected in the Dark Zone.

Glacier algae have adopted many unique strategies for surviving in this extreme environment, yet one has elevated their global importance. Ice surfaces are subject to intense solar radiation, due to 24 hours of sunlight during the polar summer. As such, glacier algae have developed a dark pigmentation within their cells to help shield them from radiation. Because of this pigmentation and their high abundance in the Dark Zone, several studies have now concluded that pigmented algae have the greatest impact on ice surface darkening compared to any other nonalgal impurity, including black carbon or dust melting out of ancient ice. Yet, at present, algal influence on surface darkening, known as bioalbedo, is not being factored into melt rate models for the GrIS. 

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The GrIS has experienced a significant increase in net mass loss in the past two decades, increasing from 34 gigatonnes of ice per year during 1992 – 2001 to 215 gigatonnes of ice per year during 2002 – 2011, with surface ice accounting for nearly 68% of that increase since 2009.  As temperatures continue to rise in the Arctic, seasonal snow packs, which form during the winter and melt away in the spring, will retreat earlier, leading to an extended season of bare ice exposure. This will result in more surface ice melt and nutrient and liquid water availability, perfect growing conditions for glacier algae blooms. Furthermore, the burning of fossil fuels releases nutrients necessary for cell growth, such as nitrogen, into the atmosphere, which are transported to surface ice environments that are otherwise nutrient-limited.  This extra abundance of nutrients allows for microbial communities to spend less energy on producing nutrients and more energy on growth.  

It can therefore be expected that these blooms seen on the GrIS, and on glaciers and ice sheets throughout the cryosphere, will continue to escalate leading to further darkening of the sheet and increased melt rates, resulting in increased sea-level rising. 

Featured image by: Christine Zenino

The post Algae Blooms are Accelerating Melt Rates on the Greenland Ice Sheet appeared first on Earth.Org.