The oceans are warming faster than previously thought, according to a pair of new studies released this weekend and published in the scientific journal Natural Climate Change. This conclusion is largely due to enhanced information gathering in the southern oceans, which was limited in the past. The research teams compared previous ocean warming figures, based on the less complete data, with projections based on information they were able to obtain from more detailed studies. They found that from 1970 through 2004, increases in ocean temperatures exceeded those earlier figures.
"The global ocean stores more than 90 percent of the heat associated with observed greenhouse-gas-attributed global warming," opens the summary of the study "Quantifying underestimates of long-term upper-ocean warming," produced by scientists from the Lawrence Livermore National Laboratory and the California Institute of Technology.
They conclude that studies of global ocean warming since 1970 are low. "This underestimation is attributed to poor sampling of the Southern Hemisphere, and limitations of the analysis methods that conservatively estimate temperature changes in data-sparse regions," they say. "Making adjustments to their model, based on recent access to additional information, they say "yields large increases to current global upper-ocean heat content change estimates, and have important implications for sea level, the planetary energy budget and climate sensitivity assessments."
The other study, "Deep-ocean contribution to sea level and energy budget not detectable over the past decade," also by CalTech scientists, attempted to measure the amount of sea level rise attributable to upper ocean vs deep ocean warming and when that warming occurred. Sea level rise occurs as warmer water expands.
"As the dominant reservoir of heat uptake in the climate system, the world’s oceans provide a critical measure of global climate change," says the study's summary.
They found that the deep ocean may not have gotten warmer in the last decade, but significant warming has occurred in the upper level of the ocean. They acknowledge "large uncertainty" in their calculations about the deep ocean since they were extrapolated from information based primary on upper ocean measurements.
"It's likely that due to the poor observational coverage, we just haven't been able to say definitively what the long-term rate of Southern Hemisphere ocean warming has been," lead author of the first study Dr. Paul Durack told the BBC. "It's a really pressing problem—we're trying as hard as we can, as scientists, to provide the best information from the limited observations we have."
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Though made in large part of plastic, glass, ceramics, gold and copper, they also contain critical resources. The gallium used for LEDs and the camera flash, the tantalum in capacitors and indium that powers the display were all pulled from the ground — at a price for nature and people.
"Mining raw materials is always problematic, both with regard to human rights and ecology," said Melanie Müller, raw materials expert of the German think tank SWP. "Their production process is pretty toxic."
The gallium and indium in many phones comes from China or South Korea, the tantalum from the Democratic Republic of Congo or Rwanda. All in, such materials comprise less than ten grams of a phone's weight. But these grams finance an international mining industry that causes radioactive earth dumps, poisoned groundwater and Indigenous population displacement.
Environmental Damage: 'Nature Has Been Overexploited'
The problem is that modern technologies don't work without what are known as critical raw materials. Collectively, solar panels, drones, 3D printers and smartphone contain as many as 30 of these different elements sourced from around the globe. A prime example is lithium from Chile, which is essential in the manufacture of batteries for electric vehicles.
"No one, not even within the industry, would deny that mining lithium causes enormous environmental damage," Müller explained, in reference to the artificial lakes companies create when flushing the metal out of underground brine reservoirs. "The process uses vast amounts of water, so you end up with these huge flooded areas where the lithium settles."
This means of extraction results in the destruction and contamination of the natural water system. Unique plants and animals lose access to groundwater and watering holes. There have also been reports of freshwater becoming salinated due to extensive acidic waste water during lithium mining.
But lithium is not the only raw material that causes damage. Securing just one ton of rare earth elements produces 2,000 tons of toxic waste, and has devastated large regions of China, said Günther Hilpert, head of the Asia Research Division of the German think tank SWP.
He says companies there have adopted a process of spraying acid over the mining areas in order to separate the rare earths from other ores, and that mined areas are often abandoned after excavation.
"They are no longer viable for agricultural use," Hilpert said. "Nature has been overexploited."
China is not the only country with low environmental mining standards and poor resource governance. In Madagascar, for example, a thriving illegal gem and metal mining sector has been linked to rainforest depletion and destruction of natural lemur habitats.
States like Madagascar, Rwanda and the DRC score poorly on the Environmental Performance Index that ranks 180 countries for their effort on factors including conservation, air quality, waste management and emissions. Environmentalists are therefore particularly concerned that these countries are mining highly toxic materials like beryllium, tantalum and cobalt.
But it is not only nature that suffers from the extraction of high-demand critical raw materials.
"It is a dirty, toxic, partly radioactive industry," Hilpert said. "China, for example, has never really cared about human rights when it comes to achieving production targets."
Dirty, Toxic, Radioactive: Working in the Mining Sector
One of the most extreme examples is Baotou, a Chinese city in Inner Mongolia, where rare earth mining poisoned surrounding farms and nearby villages, causing thousands of people to leave the area.
In 2012, The Guardian described a toxic lake created in conjunction with rare earth mining as "a murky expanse of water, in which no fish or algae can survive. The shore is coated with a black crust, so thick you can walk on it. Into this huge, 10 sq km tailings pond nearby factories discharge water loaded with chemicals used to process the 17 most sought after minerals in the world."
Local residents reported health issues including aching legs, diabetes, osteoporosis and chest problems, The Guardian wrote.
South Africa has also been held up for turning a blind eye to the health impacts of mining.
"The platinum sector in South Africa has been criticized for performing very poorly on human rights — even within the raw materials sector," Müller said.
In 2012, security forces killed 34 miners who had been protesting poor working conditions and low wages at a mine owned by the British company Lonmin. What became known as the "Marikana massacre" triggered several spontaneous strikes across the country's mining sector.
Müller says miners can still face exposure to acid drainage — a frequent byproduct of platinum mining — that can cause chemical burns and severe lung damage. Though this can be prevented by a careful waste system.
Some progress was made in 2016 when the South African government announced plans to make mining companies pay $800 million (€679 million) for recycling acid mine water. But they didn't all comply. In 2020, activists sued Australian-owned mining company Mintails and the government to cover the cost of environmental cleanup.
Another massive issue around mining is water consumption. Since the extraction of critical raw materials is very water intensive, drought prone countries such as South Africa, have witnessed an increase in conflicts over supply.
For years, industry, government and the South African public debated – without a clear agreement – whether companies should get privileged access to water and how much the population may suffer from shortages.
Mining in Brazil: Replacing Nature, People, Land Rights
Beyond the direct health and environmental impact of mining toxic substances, quarrying critical raw materials destroys livelihoods, as developments in Brazil demonstrate.
"Brazil is the major worldwide niobium producer and reserves in [the state of] Minas Gerais would last more than 200 years [at the current rate of demand]," said Juliana Siqueira-Gay, environmental engineer and Ph.D. student at the University of São Paulo.
While the overall number of niobium mining requests is stagnating, the share of claims for Indigenous land has skyrocketed from 3 to 36 percent within one year. If granted, 23 percent of the Amazon forest and the homeland of 222 Indigenous groups could fall victim to deforestation in the name of mining, a study by Siqueira-Gay finds.
In early 2020, Brazilian President Jair Bolsonaro signed a bill which would allow corporations to develop areas populated by Indigenous communities in the future. The law has not yet entered into force, but "this policy could have long-lasting negative effects on Brazil's socio-biodiversity," said Siqueira-Gay.
One example are the niobium reserves in Seis Lagos, in Brazil's northeast, which could be quarried to build electrolytic capacitors for smartphones.
"They overlap the Balaio Indigenous land and it would cause major impacts in Indigenous communities by clearing forests responsible for providing food, raw materials and regulating the local climate," Siqueira-Gay explained.
She says scientific good practice guidelines offer a blueprint for sustainable mining that adheres to human rights and protects forests. Quarries in South America — and especially Brazil — funded by multilaterial banks like the International Finance Corporation of the World Bank Group have to follow these guidelines, Siqueira-Gay said.
They force companies to develop sustainable water supply, minimize acid exposure and re-vegetate mined surfaces. "First, negative impacts must be avoided, then minimized and at last compensated — not the other way around."
Reposted with permission from DW.