Global Warming...New Report...and it ain't happy news

Britain’s last 30 years have been 6 per cent wetter and almost 1C hotter than the preceding three decades, the Met Office says.

Its annual climate update also says that the country’s 10 hottest years have all occurred since 2002, with last year being the third warmest on record after 2014 and 2006.

As well as being among the hottest, 2020 was also the fifth wettest and eight sunniest on record, the report says.

It was the first year that annual values for rainfall, temperature and sunshine were all in the top 10 at the same time.

Sea level rise has accelerated in recent years, the report adds. The rate of sea level rise was 1.5mm a year from the start of the 20th century. However, over the period 1993-2019, it increased to over 3mm a year.

“It’s a very high level of melting and it will probably change the face of Greenland because it will be a very strong driver for an acceleration of future melting, and therefore sea-level rise,” said Marco Tedesco, a glacier expert at Columbia University and adjunct scientist at Nasa.

Tedesco said a patch of high pressure is sucking and holding warmer air from further south “like a vacuum cleaner” and holding it over eastern Greenland, causing an all-time record temperature of 19.8C in the region on Wednesday. As seasonal snow melts away, darker core ice is exposed, which then melts and adds to sea level rise.

“We had these sort of atmospheric events in the past but they are now getting longer and more frequent,” Tedesco said.

“The snow is like a protective blanket so once that’s gone you get locked into faster and faster melting, so who knows what will happen with the melting now. It’s amazing to see how vulnerable these huge, giant areas of ice are. I’m astonished at how powerful the forces acting on them are.”

Greenland’s melting season usually lasts from June to August. The Danish government data shows that it has lost more than 100bn tons of ice since the start of June this year and while the severity of melting is less than in 2019 – when 11bn tons of ice was lost in a single day – the area affected is much larger in 2021.

“It’s hard to say if it will be a record year for melting this year but there is a ton of warm and moist air over the ice sheet that’s causing an amazing amount of melt,” said Brad Lipovsky, a glaciologist at the University of Washington.

“The alarming thing to me is the political response, or lack of it. Sea-level rise is like a slow-moving train, but once it gets rolling you can’t stop it. It’s not great news.”

If all of the ice in Greenland melted, the global sea level would jump by about 6 meters (20ft) and although this is unlikely to happen on any sort of foreseeable timescale, scientists have warned that the world’s largest island is reaching a tipping point due to the pressures being exerted upon it by global heating.

Greenland’s ice is melting faster than any time in the past 12,000 years, scientists have calculated, with the ice loss running at a rate of around one million tons a minute in 2019. Greenland and the earth’s other polar region of Antarctica have together lost 6.3tn tons of ice since 1994.

This rate of ice loss, which is accelerating as temperatures continue to increase, is changing ocean currents, altering marine ecosystems and posing a direct threat to the world’s low-lying coastal cities that risk being inundated by flooding. A 2019 research paper found the Greenland ice sheet could add anything between 5cm and 33cm to global sea levels by the end of the century and the world is on track for “the mid to upper end of that”, Lipovsky said.

“It’s very worrisome,” said Tedesco. “The action is clear – we need to get to net zero emissions but also we need to protect exposed populations along the coast. This is going to be a huge problem for our coastal cities.”

Michael Mann, distinguished professor of atmospheric science at Pennsylvania State University, said this would be the last IPCC assessment that can make a real difference in policy terms, before we exceed 1.5C and the ambitions of the Paris agreement.

“Climate change is now causing amplified weather extremes of the sort we’ve been witnessing this summer – droughts, heatwaves, wildfires, floods, superstorms,” he said. “The impacts of climate change are no longer subtle. We see them playing out in real time in the form of these unprecedented extreme weather disasters.”

“​​It is unequivocal.” Those stark three words are the first in the Intergovernmental Panel on Climate Change’s new report. The climate crisis is unequivocally caused by human activities and is unequivocally affecting every corner of the planet’s land, air and sea already.

The report, produced by hundreds of the world’s top scientists and signed off by all the world’s governments, concludes that it could get far worse if the slim chance remaining to avert heating above 1.5C is not immediately grasped.

The scientific language of the report is cold and clear but cannot mask the heat and chaos that global heating is unleashing on the world. We have already caused 1C of heating, getting perilously close to the 1.5C danger limit agreed in the Paris climate deal. Downpours of rain have been accelerating since the 1980s.

Accelerating melting of ice has poured trillions of tonnes of water into the oceans, where oxygen levels are falling – suffocating the seas – and acidity is rising. Sea level has already risen by 20cm, with more now irreversibly baked in.

The greenhouse gas emissions spewed out by fossil fuel burning, forest destruction and other human activities are now clearly destabilising the mild climate in which civilisation began, the report shows. Carbon dioxide levels in the air are now at their highest point for at least 2m years.

When was the last time we saw heating this fast? At least 2,000 years ago and probably 100,000 years. Temperatures this high? At least 6,500 years. Sea level rising so fast? At least 3,000 years. Oceans so acidic? Two million years.

All this is already hurting people everywhere, the report spells out. Heatwaves and the heavy rains that lead to flooding have become more intense and more frequent since the 1950s, affecting more than 90% of the world’s regions, according to the report. Drought is increasing in more than 90% of the regions for which there is good data. It is more than 66% likely that the number of major hurricanes and typhoons has increased since the 1970s.

So what of the future? Some heating is already inevitable. We will definitely hit 1.5C in the next two decades, whatever happens to emissions, the IPCC finds. The only good news is that keeping to that 1.5C is not yet impossible.

But it will require “immediate, rapid and large-scale reductions” in emissions, say the scientists, of which there is no sign to date. Even cutting emissions, but more slowly, leads to 2C and significantly more suffering for all life on Earth.

If emissions do not fall in the next couple of decades, then 3C of heating looks likely – a catastrophe. And if they don’t fall at all, the report says, then we are on track for 4C to 5C, which is apocalypse territory.

The report is clear there are no cliff-edges to the climate crisis. Each tonne of carbon pumped out increases the impacts and risks of extreme heat, floods and droughts and so every tonne of carbon matters. It will never be too late to act, the report shows. Instead, the real question is how bad will it get?

For example, extreme heatwaves expected once every 50 years without any global heating are already happening every decade. With 1.5C warming, these will happen about every 5 years; with 2C, every 3.5 years; and with 4C, once every 15 months. More heating also means more disruptions to the monsoon rains on which billions depend for food.

More emissions also means the land and oceans become weaker at soaking up that carbon pollution, making heating even worse. With immediate rapid cuts, the natural world can still soak up 70% of our emissions. With no cuts, that falls to just 40%.

One of the most blunt sections of the report begins: “Many changes due to past and future greenhouse gas emissions are irreversible for centuries to millennia.” This particularly affects the world’s oceans and ice, which absorb 96% of global heating, meaning ice will keep melting and the oceans rising towards our many crowded coastal cities.

The likely range is between 28cm and 100cm by the end of the century. But it could be 200cm by then, or 500cm by 2150, the report warns. Extreme sea level events, such as coastal flooding, that occurred just once per century in the recent past are projected to happen at least annually in 60% of places by 2100.

“That might seem like a long way away but there are millions of children already born who should be alive well into the 22nd century,” says Prof Jonathan Bamber, at the University of Bristol, UK, and a report author.

The many scientific advances since the last comprehensive IPCC report in 2013 mean better projections for specific regions of the world. It finds nowhere is safe. For example, even at 1.5C of heating, heavy rain and flooding are projected to intensify in Europe, North America and most regions of Africa and Asia.

“We can no longer assume that citizens of more affluent and secure countries like Canada, Germany, Japan and the US will be able to ride-out the worst excesses of a rapidly destabilising climate,” says Prof Katharine Hayhoe, chief scientist at The Nature Conservancy. “It’s clear we’re all in the same boat – facing a challenge that will affect every one of us within our lifetimes.”

The report is the sixth by the IPCC but the first to assess the risk of tipping points thoroughly. These are abrupt and irreversible changes to crucial Earth systems that have huge impacts and are of increasing concern to scientists. The collapse of major Atlantic currents, ice caps, or the Amazon rainforest “cannot be ruled out”, the report warns.

“For the tipping points, it’s clear that every extra tonne of CO2 emitted today is pushing us into a minefield of feedback effects tomorrow,” says Prof Dave Reay, at the University of Edinburgh, UK.

So what can be done? The final section of the IPCC report addresses how future climate change can be limited. It finds that 2,400bn tonnes of CO2 have been emitted by humanity since 1850, and that we can only leak another 400bn tonnes to have a 66% chance of keeping to 1.5C.

In other words, we have blown 86% of our carbon budget already, though the report says the science is clear that if emissions are slashed then temperatures will stop rising in a decade or two and the increases in deadly extreme events will be strongly limited.

“Unless there are immediate rapid and large-scale reductions in greenhouse gas emissions, limiting warming to 1.5C will be beyond reach,” says Abdalah Mokssit, secretary of the IPCC.

“But we never dictate any policy to any country – it is for the governments to take the decisions.”

The scientists have now spoken, louder and clearer than ever before. Now it is for the politicians to act.

As drought persists across more than 95% of the American West, water elevation at the Hoover Dam has sunk to record-low levels, endangering a source of hydroelectric power for an estimated 1.3 million people across California, Nevada and Arizona.

The water level at Lake Mead, the Colorado River reservoir serving the Hoover Dam, fell to 1,068 ft. in July, the lowest level since the lake was first filled following the dam’s construction in the 1930s. This month, the federal government is expected to declare a water shortage on the Colorado River for the first time, triggering cutbacks in water allocations to surrounding states from the river.

Widespread drought conditions throughout the Southwest over the past 20 years have led to a more than 130-foot drop in the water level at Lake Mead since 2000.

The Bureau of Reclamation’s latest projections, from July, show the lake’s water level falling another 31 ft., to 1,037 ft., by June 2023.
For dams to produce power, they rely on the immense pressure created by the body of water they are blocking. As water levels go down, less pressure is exerted and the dams in turn produce less hydroelectric energy, which means the dam can produce less power.

While 1,068 ft. of depth in a body of water as large as Lake Mead seems massive, every foot of water lost equates to about six megawatts less power generated in a year, according to Patti Aaron, public affairs officer at the U.S. Bureau of Reclamation, which operates and maintains the power plant. Six megawatts roughly translates to the power consumed by 800 homes.
If the water level drops 118 ft. from July’s level, to 950 ft., it would fall below the turbines and the dam must shut down, Ms. Aaron said.

The power declines are significant. At 1,200 ft. water elevation—where it was in the year 2000, when water levels were among the dam’s highest levels—the dam can power up to 450,000 homes. At the current elevation, that figure falls to 350,000.

The Hoover Dam is one of the nation’s largest hydroelectric facilities. About 23% of its power output serves Nevada, 19% serves Arizona, and most of the remainder serves Southern California.

The California Independent System Operator, or Caiso, which oversees the state’s power grid, last summer resorted to rolling blackouts during a West-wide heat wave that constrained the state’s ability to import electricity. The supply crunch was most acute in the evening, after solar production declined.

Furthermore, climate change stabilizes a novel and likely irreversible low productivity state of this fish stock that is not adapted to a fast warming environment. We hence argue that ignorance of non-linear resource dynamics has caused the demise of an economically and culturally important social-ecological system which calls for better adaptation of fisheries systems to climate change.

We show that for thousands of years, humans have concentrated in a surprisingly narrow subset of Earth’s available climates, characterized by mean annual temperatures around ∼13 °C. This distribution likely reflects a human temperature niche related to fundamental constraints. We demonstrate that depending on scenarios of population growth and warming, over the coming 50 y, 1 to 3 billion people are projected to be left outside the climate conditions that have served humanity well over the past 6,000 y. Absent climate mitigation or migration, a substantial part of humanity will be exposed to mean annual temperatures warmer than nearly anywhere today.

All species have an environmental niche, and despite technological advances, humans are unlikely to be an exception. Here, we demonstrate that for millennia, human populations have resided in the same narrow part of the climatic envelope available on the globe, characterized by a major mode around ∼11 °C to 15 °C mean annual temperature (MAT). Supporting the fundamental nature of this temperature niche, current production of crops and livestock is largely limited to the same conditions, and the same optimum has been found for agricultural and nonagricultural economic output of countries through analyses of year-to-year variation. We show that in a business-as-usual climate change scenario, the geographical position of this temperature niche is projected to shift more over the coming 50 y than it has moved since 6000 BP. Populations will not simply track the shifting climate, as adaptation in situ may address some of the challenges, and many other factors affect decisions to migrate. Nevertheless, in the absence of migration, one third of the global population is projected to experience a MAT >29 °C currently found in only 0.8% of the Earth’s land surface, mostly concentrated in the Sahara. As the potentially most affected regions are among the poorest in the world, where adaptive capacity is low, enhancing human development in those areas should be a priority alongside climate mitigation.

Global warming will affect ecosystems as well as human health, livelihoods, food security, water supply, and economic growth in many ways (1, 2). The impacts are projected to increase steeply with the degree of warming. For instance, warming to 2 °C, compared with 1.5 °C, is estimated to increase the number of people exposed to climate-related risks and poverty by up to several hundred million by 2050. It remains difficult, however, to foresee the human impacts of the complex interplay of mechanisms driven by warming (1, 3). Much of the impact on human well-being will depend on societal responses. There are often options for local adaptations that could ameliorate effects, given enough resources (4). At the same time, while some regions may face declining conditions for human thriving, conditions in other places will improve. Therefore, despite the formidable psychological, social, and political barriers to migration, a change in the geographical distribution of human populations and agricultural production is another likely part of the spontaneous or managed adaptive response of humanity to a changing climate (5). Clearly there is a need to understand the climatic conditions needed for human thriving. Despite a long and turbulent history of studies on the role of climate, and environment at large, on society in geography and beyond (6), causal links have remained difficult to establish, and deterministic claims largely refuted, given the complexities of the relationships in question (7). Rather than reentering the murky waters of environmental determinism (8, 9), here we take a fresh look at this complex and contentious issue. We mine the massive sets of demographic, land use, and climate information that have become available in recent years to ask what the climatic conditions for human life have been across the past millennia, and then examine where those conditions are projected to occur in the future.

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In summary, our results suggest a strong tension between expected future population distributions and the future locations of climate conditions that have served humanity well over the past millennia. So far, the scope for local adaptation has been the dominant focus for analyses of possible responses to a changing climate (4), despite a striking lack of realized adaptation in most regions (12, 13). It is not too late to mitigate climate change and to improve adaptive capacity, especially when it comes to boosting human development in the Global South (45, 46). However, our approach naturally raises the question of what role redistribution of populations may come to play. Migration can have beneficial effects to societies, including a boost to research and innovation (47). However, on larger scales, migration inevitably causes tension, even now, when a relatively modest number of ∼250 million people live outside their countries of birth (48). Looking at the benefits of climate mitigation in terms of avoided potential displacements may be a useful complement to estimates in terms of economic gains and losses.

Researchers say climate change is driving the melting, which has seen Kebnekaise lose more than 20 metres in height since the mid-1990s

Sweden’s only remaining mountaintop glacier, which until 2019 was also its highest peak, lost another two metres in height in the past year due to rising air temperatures driven by climate change, Stockholm University says.

In 2019, the south peak of the Kebnekaise massif was demoted to second in the rankings of Swedish mountains after a third of its glacier melted. Kebnekaise’s north peak, where there is no glacier, is now the highest in the Nordic country.

Vote. Divest. Plant trees. Recycle. Remove fossil fuel subsidies. Go renewable. We don’t need to accept the inevitable demise of life on the planet

Imagine if scientists had just informed the world that there was a huge meteor heading our way that would likely wipe out life as we knew it. Or if the sun started doing really dangerous and frightening things that were likely to fry us. What would we do? Party like there was really no tomorrow? Or just crawl under the doona to wait out the inevitable?

The silver lining to the climate change catastrophe is that it’s not caused by a meteor, or the sun. It’s us. And because we’ve caused it, and we know how, we can fix it – or at least slow it down a lot.
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So what would it take to turn things around?

Every tonne of CO2 emitted adds to global warming and is doing us harm. Every fraction of a degree matters. I’m reminded of a successful anti-smoking campaign from a few years ago that made the point that while every cigarette is doing terrible things to your body, as soon as you stop, things start to get better. It’s not a perfect analogy, but if every molecule of emitted greenhouse gas is contributing to killing life on Earth, then every molecule that we avoid emitting is part of the solution.

So here’s my top 10 things to do (Mr Morrison, the first three are for you):

1. Electrify everything – energy, transport and manufacturing.

2. Power it all from renewables, obviously.

3. Remove all fossil fuel subsidies (more than $10bn from taxpayers per year) and use this money to transform the grid.

4. Stop, or at least greatly reduce, eating the products of methane-belching cows, the farming of which is also responsible for most land-clearing in Australia.

5. Plant trees – still the best way to draw down CO2.

6. Stop buying so much stuff – everything has a carbon cost.

7. Reuse, retain, recycle. You know the drill.

8. Move your money out of banks, insurance companies and superannuation funds that invest in fossil fuels – it only takes a few clicks.

9. Give your time, your talent or your treasure to organisations that are fighting the good fight – there is power in the collective.

10. And most of all, ask yourself: is my elected representative threatening the lives of my children and grandchildren, either by actively blocking climate action, or by simply delaying in the hope that some uninvented technology will fall from sky? You can help save the world with a pencil. Vote. Them. Out.

Humans can be dumb, greedy and selfish, but also smart, innovative and caring.

Desmond Tutu once exhorted: “Do your little bit of good where you are; it’s those little bits of good put together that overwhelm the world.” The IPCC report tells us we can, collectively, put our bits of good together and find a way out of this mess.

Rain has fallen on the summit of Greenland’s huge ice cap for the first time on record. Temperatures are normally well below freezing on the 3,216-metre (10,551ft) peak, and the precipitation is a stark sign of the climate crisis.

Scientists at the US National Science Foundation’s summit station saw rain falling throughout 14 August but had no gauges to measure the fall because the precipitation was so unexpected. Across Greenland, an estimated 7bn tonnes of water was released from the clouds.

The rain fell during an exceptionally hot three days in Greenland when temperatures were 18C higher than average in places. As a result, melting was seen in most of Greenland, across an area about four times the size of the UK.

The recent report from the Intergovernmental Panel on Climate Change concluded it was “unequivocal” that carbon emissions from human activities were heating the planet and causing impacts such as melting ice and rising sea level.

In May, researchers reported that a significant part of the Greenland ice sheet was nearing a tipping point, after which accelerated melting would become inevitable even if global heating was halted.
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Greenland also had a large-scale melting episode in July, making 2021 one of just four years in the past century to see such widespread melting. The other years were 2019, 2012 and 1995. The rain and melt on 14-16 August came at the latest point in the year a major event has been recorded.

The cause of the July and August melting was the same – warm air being pushed up over Greenland and held there. These “blocking” events are not uncommon but seem to be becoming more severe, according to scientists.
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