Posts

Climate change is weakening the ocean currents that shape weather on both sides of the Atlantic

by Bob Berwyn, Inside Climate News


Highlights

  • The Atlantic Meridional Overturning Circulation is a system of ocean currents that distributes heat energy from the tropics towards the poles and causes cold water to flow towards the equator. This system is what shaped the climate of eastern North America and Western Europe, allowing the development of civilizations in the region
  • The system is weakening now more than ever within a 1000 year time span due to climate change
  • This could lead to extreme weather, sea-level rise along the coasts, ocean heatwaves, droughts, and heatwaves on land
  • Commercial and recreational fishing may be jeopardized due to the warming of waters along the continental shelf according to Vincent Saba of the National Oceanic and Atmospheric Administration’s Northeast Fisheries Science Center
  • The last significant shutdown of the Circulation happened 11,000 years ago and resulted in major climate changes

Scientists are increasingly warning that to avoid catastrophic impacts from climate change, the world’s governments must implement policies for massive greenhouse gas emissions reductions and begin a drawdown of carbon from the atmosphere within ten years. With 9 of 15 global tipping points now active, what we do today can either unleash an inhospitable hothouse Earth or secure a safe climate well into the future. For a safe and healthy future for all, endorse the Climate-Safe California Platform to implement scalable solutions that can reverse the climate crisis.


Read More: https://insideclimatenews.org/news/25022021/climate-change-ocean-currents-atlantic

 

‘Teetering at the edge’: Scientists warn of rapid melting of Antarctica’s ‘Doomsday glacier’

by Harry Cockburn, The Independent 


Highlights

  • The Thwaites glacier in Antarctica, which is almost the same size as the United Kingdom, is melting and its collapse would raise sea levels close to 2 feet
  • This glacier is considered to be very important to the health of other neighboring glaciers. Its collapse may result in the melting of more glaciers according to Paul Cutler of America’s National Science Foundation:

“It is a keystone for the other glaciers around it in West Antarctica… If you remove it, other ice will potentially start draining into the ocean too.”

  • Melt from this glacier already accounts for 4% of global sea-level rise
  • Earlier this year scientists discovered the presence of warm water under the glacier
  • The world has seen a doubling of sea-level rise since 1990
  • Though the Antarctic is experiencing warming, temperatures are rising higher in the Arctic where Siberia has experienced a record high of 100 degrees Fahrenheit

The Climate Center’s Rapid Decarbonization Campaign sets a goal that by 2025, California will have enacted the bold, accelerated policies required by science to double emissions reductions, accelerate drawdown, and secure resilient communities by 2030.


Read More: https://www.independent.co.uk/environment/thwaites-glacier-antarctic-melting-doomsday-climate-a9616966.html

Global warming is speeding up Earth’s massive ocean currents- another mega-scale consequence of climate change

By Paul Voosen, Science Magazine

And see here, The world’s oceans are speeding up — another mega-scale consequence of climate change


Highlights:

Ocean currents have been increasing in energy for the last few decades, which can affect jet streams, weather patterns, marine wildlife and the amount of heat stored in the ocean’s depths.

  • Three-quarters of the world’s ocean waters have sped up their pace in recent decades, a massive development that was not expected to occur until climate warming became much more advanced.
  • Scientists aren’t certain of all the consequences of this speedup yet. But they may include impacts in key regions along the eastern coasts of continents, where several currents have intensified. The result in some cases has been damaging ocean hotspots that have upended marine life.
  • The study notes that in extreme climate warming scenarios, a speedup of global winds also occurs — but the change was expected to peak at the end of this century, after vastly more warming than has happened so far. This suggests the Earth might actually be more sensitive to climate change than our simulations can currently show, McPhaden said.
  • As waters warm, less carbon dioxide can be absorbed by oceans, limiting sequestration and shifting weather patterns
  • Heat may also be stored in the depths of the ocean which can help slow warming on land

The Climate Center supports policies that enhance healthy ecosystems on land and at sea, to sustain biodiversity and catalyze additional carbon sequestration, key to achieving net-negative emissions by 2030.


Read More: https://www.sciencemag.org/news/2020/02/global-warming-speeding-earth-s-massive-ocean-currents

History’s largest mining operation is about to begin underwater—and the consequences are unimaginable

by Wil S. Hylton

Unless you are given to chronic anxiety or suffer from nihilistic despair, you probably haven’t spent much time contemplating the bottom of the ocean. Many people imagine the seabed to be a vast expanse of sand, but it’s a jagged and dynamic landscape with as much variation as any place onshore. Mountains surge from underwater plains, canyons slice miles deep, hot springs billow through fissures in rock, and streams of heavy brine ooze down hillsides, pooling into undersea lakes…


His case for seabed mining is straightforward. Barron believes that the world will not survive if we continue burning fossil fuels, and the transition to other forms of power will require a massive increase in battery production. He points to electric cars: the batteries for a single vehicle require 187 pounds of copper, 123 pounds of nickel, and 15 pounds each of manganese and cobalt. On a planet with 1 billion cars, the conversion to electric vehicles would require several times more metal than all existing land-based supplies—and harvesting that metal from existing sources already takes a human toll. Most of the world’s cobalt, for example, is mined in the southeastern provinces of the Democratic Republic of Congo, where tens of thousands of young children work in labor camps, inhaling clouds of toxic dust during shifts up to 24 hours long. Terrestrial mines for nickel and copper have their own litany of environmental harms. Because the ISA is required to allocate some of the profits from seabed mining to developing countries, the industry will provide nations that rely on conventional mining with revenue that doesn’t inflict damage on their landscapes and people.

The root of the problem: Finding solutions for the Great Barrier Reef

by Maddie Maffia, CCP

This summer, I am studying land-use practices and their impacts on the Great Barrier Reef (GBR) in Australia. The GBR is the most diverse coral reef ecosystem in the world. Sadly, it has lost 80% of its coral reef coverage in the northern portion of the reef over the past decade. One of the primary problems for the coral reefs comes from terrestrial land-use management practices.

The majority of the land off the coast of Queensland is primarily used for coastal urbanization, growing sugar cane, cow grazing, and rainforest conservation. However, the area adjacent to the coral reefs is largely used for sugar cane and cow grazing. This land-use practice has immense effects on the GBR due to the increase in runoff, which increases the amount of sediment and nutrient accumulation in the waterways. For example, the coral and algae live in a mutually-beneficial relationship with each other, and excess nutrients in the reef can upset the natural balance of these ecosystems. The plants grab the extra nutrients and grow to dominate in size or quantity more than they normally would. This, in turn, allows the algae to outcompete the corals, which leads to a decrease in coral reef coverage. In addition to this, farmers tend to maximize their profit by placing their farms adjacent to waterways to allow their cows and crops access to freshwater. This additionally increases the rate of transported pollution and furthers the degradation of coral reefs.

The Australian government is very proactive in passing marine legislation to protect the coral reefs, however, the legislation is covering up the problem rather than stopping it. To prevent pollution from entering the waterways, the government needs to address how farmers use their land to make it more sustainable and viable for the coral reefs downstream. Strategies like carbon farming – where farmers use no-till methods and cover crops to quickly sequester carbon and improve soil fertility without toxic fertilizers and pesticides – are undoubtedly going to be the way of the future.

This idea of fixing the root of the problem can easily be translated back to the United States. Switching from fossil fuel use to all-electric renewable power sources (with battery storage) will be key to tackling climate change. How we get there remains to be seen. Many policy wonks agree that we will need a meaningful (high) carbon tax that can help fund the transition and retraining that will be required. However, trying to solve our problems downstream – whether that’s in the coral reefs or at the end of millions of tailpipes – is not efficient or effective. Heading upstream to the source to face the problem head-on will save time, money, and lives.  As we phase out fossil fuels, we will also phase out thousands of pollution-related deaths in favor of a healthy sustainable existence and a stable planet.

Heatwaves sweeping oceans ‘like wildfires’, scientists reveal

by Damian Carrington, The Guardian

The number of heatwaves affecting the planet’s oceans has increased sharply, scientists have revealed, killing swathes of sea-life like “wildfires that take out huge areas of forest”.

The damage caused in these hotspots is also harmful for humanity, which relies on the oceans for oxygen, food, storm protection and the removal of climate-warming carbon dioxide the atmosphere, they say.

Global warming is gradually increasing the average temperature of the oceans, but the new research is the first systematic global analysis of ocean heatwaves, when temperatures reach extremes for five days or more.

The research found heatwaves are becoming more frequent, prolonged and severe, with the number of heatwave days tripling in the last couple of years studied. In the longer term, the number of heatwave days jumped by more than 50% in the 30 years to 2016, compared with the period of 1925 to 1954.

Read more: https://www.theguardian.com/environment/2019/mar/04/heatwaves-sweeping-oceans-like-wildfires-scientists-reveal?CMP=share_btn_tw