03/11/2021

(The Conversation) The Science Everyone Needs To Know About Climate Change, In 6 Charts

The Conversation - 

Scientific instruments in space today can monitor hurricane strength, sea level rise, ice sheet loss and much more. Christina Koch/NASA

Author
 is Senior Scientist, University of Colorado Boulder     
With the United Nations’ climate conference in Scotland turning a spotlight on climate change policies and the impact of global warming, it’s useful to understand what the science shows.

I’m an atmospheric scientist who has worked on global climate science and assessments for most of my career. Here are six things you should know, in charts.

What’s driving climate change

The primary focus of the negotiations is on carbon dioxide, a greenhouse gas that is released when fossil fuels – coal, oil and natural gas – are burned, as well as by forest fires, land use changes and natural sources.

The Industrial Revolution of the late 1800s started an enormous increase in the burning of fossil fuels. It powered homes, industries and opened up the planet to travel.

That same century, scientists identified carbon dioxide’s potential to increase global temperatures, which at the time was considered a possible benefit to the planet.

 Systematic measurements started in the mid-1900s and have shown a steady increase in carbon dioxide, with the majority of it directly traceable to the combustion of fossil fuels.

Once in the atmosphere, carbon dioxide tends to stay there for a very long time. A portion of the carbon dioxide released through human activities is taken up by plants, and some is absorbed directly into the ocean, but roughly half of all carbon dioxide emitted by human activities today stays in the atmosphere — and it likely will remain there for hundreds of years, influencing the climate globally.

During the first year of the pandemic in 2020, when fewer people were driving and some industries briefly stopped, carbon dioxide emissions from fuels fell by roughly 6%. But it didn’t stop the rise in the concentration of carbon dioxide because the amount released into the atmosphere by human activities far exceeded what nature could absorb.

If civilization stopped its carbon dioxide-emitting activities today, it would still take many hundreds of years for the concentration of carbon dioxide in the atmosphere to fall enough naturally to bring the planet’s carbon cycle back into balance because of carbon dioxide’s long life in the atmosphere.

How we know greenhouse gases can change the climate

Multiple lines of scientific evidence point to the increase in greenhouse emissions over the past century and a half as a driver of long-term climate change around the world. For example:

When carbon dioxide levels have been high in the past, evidence shows temperatures have also been high. Based on Salawitch et al., 2017, updated with data to the end of 2020, CC BY



  • Long-term records from ice cores, tree rings and corals show that when carbon dioxide levels have been high, temperatures have also been high.

  • Our neighboring planets also offer evidence. Venus’ atmosphere is thick with carbon dioxide, and it is the hottest planet in our solar system as a result, even though Mercury is closer to the sun.

Temperatures are rising on every continent

The rising temperatures are evident in records from every continent and over the oceans.

The temperatures aren’t rising at the same rate everywhere, however. A variety of factors affect local temperatures, including land use that influences how much solar energy is absorbed or reflected, local heating sources like urban heat islands, and pollution.

The Arctic, for example, is warming about three times faster than the global average in part because as the planet warms, snow and ice melt makes the surface more likely to absorb, rather than reflect, the sun’s radiation. Snow cover and sea ice recede even more rapidly as a result.

What climate change is doing to the planet

Earth’s climate system is interconnected and complex, and even small temperature changes can have large impacts – for instance, with snow cover and sea levels.

Changes are already happening. Studies show that rising temperatures are already affecting precipitation, glaciers, weather patterns, tropical cyclone activity and severe storms. A number of studies show that the increases in frequency, severity and duration of heat waves, for example, affect ecosystems, human lives, commerce and agriculture.

Historical records of ocean water level have shown mostly consistent increases over the past 150 years as glacier ice melts and rising temperatures expand ocean water, with some local deviations due to sinking or rising land.

While extreme events are often due to complex sets of causes, some are exacerbated by climate change. Just as coastal flooding can be made worse by rising ocean levels, heat waves are more damaging with higher baseline temperatures.

Climate scientists work hard to estimate future changes as a result of increased carbon dioxide and other expected changes, such as world population. It’s clear that temperatures will increase and precipitation will change. The exact magnitude of change depends on many interacting factors.


A few reasons for hope

On a hopeful note, scientific research is improving our understanding of climate and the complex Earth system, identifying the most vulnerable areas and guiding efforts to reduce the drivers of climate change. Work on renewable energy and alternative energy sources, as well as ways to capture carbon from industries or from the air, are producing more options for a better prepared society.

At the same time, people are learning about how they can reduce their own impact, with the growing understanding that a globally coordinated effort is required to have a significant impact. Electric vehicles, as well as solar and wind power, are growing at previously unthinkable rates. More people are showing a willingness to adopt new strategies to use energy more efficiently, consume more sustainably and choose renewable energy.

Scientists increasingly recognize that shifting away from fossil fuels has additional benefits, including improved air quality for human health and ecosystems.

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(AU ABC News) Scott Morrison, At COP26, Pledges Funding To Support Neighbouring Pacific, Asian Nations Dealing With Climate Change

ABC News - Matthew Doran | Stephen Dziedzic

Scott Morrison's full speech to the UN Climate Summit in Glasgow.
Key Points
  • Australia's funding for neighbouring nations will increase to $2 billion over the next five years
  • Scott Morrison told the conference technology would be crucial to achieving net zero emissions
  • The federal Opposition accused Mr Morrison of embarrassing Australia on the world stage
Pacific Island leaders at the Glasgow climate conference have pressed Scott Morrison to make sharper cuts to Australia's emissions this decade as they grapple with the impacts of global warming.

The Prime Minister used his speech to reaffirm the federal government's commitment to net zero emissions by 2050 and to again stress that technological developments will be key to driving down pollution.

He also announced that the government would boost Australia's climate finance commitment, to help Pacific and South-East Asian neighbours with the effects of climate change, by $500 million to a total of $2 billion. 

But in a pointed post on social media, Fiji Prime Minister Frank Bainimarama called Mr Morrison's net zero commitment "a start." 

Mr Bainimarama said he used his meeting with Mr Morrison in Glasgow to press him to slash Australia's emissions by 2030.  

"I've now urged Scott Morrison to show us a concrete plan to halve emissions by 2030," he said on Twitter. 

Mr Morrison used his speech at Glasgow to point to Australia's uptake of solar and other renewable energy technologies.

But he also said that the Glasgow climate change conference — which has been billed as one of the most important in a generation — could only achieve so much.

The Prime Minister argued the challenge of achieving any progress on cutting carbon emissions would be "met by those who are frankly largely not in this room".

"It will be our scientists, our technologists, our engineers, our entrepreneurs, our industrialists and our financiers that will actually chart the path to net zero — and it is up to us as leaders of governments to back them in," Mr Morrison said.

"Technology will have the answers to a decarbonised economy, particularly over time." While Australia has adopted the net zero by 2050 pledge, it has not increased its short-term 2030 targets.

Tony Abbott set that benchmark in 2015, with a commitment to cut emissions by 26 to 28 per cent.

Mr Morrison said during his speech that Australia would "meet and beat" that promise — even though Australia had made no formal commitment to do so. 

"By 2030 our nationally determined contribution here at COP26 notes that our emissions in Australia will fall by 35 per cent by 2030, far exceeding our Paris commitment," he said 

When reporters asked him if Pacific leaders had asked Australia to make sharper cuts by 2030, Mr Morrison confirmed they had. 

"Well, they always have. In every discussion I've ever had with Pacific Island leaders, that is something they've always encouraged us to do," he said. 

But he argued that the net zero commitment Australia has made would still be enough to meet the expectations and "passion" embodied in the Kainaki Declaration on climate change, which was delivered at the 2019 Pacific Islands Forum leaders meeting in Tuvalu.

The federal Opposition accused Mr Morrison of embarrassing Australia on the world stage.

"It's just a continuation of the steaming pile of nothingness that we had in Australia before he left," Shadow Energy Minister Chris Bowen said.

"It is a speech devoid of substance, it's more slogans, more spin.

"Just talking about technology and saying technology over and over is not a framework for the development and adaption, or the adoption, of that technology."


Who is doing more for climate change?

Boost to 'climate resilience' funding Mr Morrison's climate finance promise will see Australia increase its funding for "climate resilience" projects over the next five years, with money going towards infrastructure projects such as roads, schools and bridges.

The extra $500 million comes on top of the $1.5 billion commitment that was announced in December 2020.

Mr Bowen said: "While any support for South-East Asian and Pacific nations is welcome, it comes off the back of the government removing Australia from the global climate change fund, and also billions of dollars of cuts to foreign aid over six successive budgets … which have impacted our region very severely.

"Scott Morrison wants a pat on the back for this announcement — he won't be getting one from us, and I doubt it he'll be getting one from Pacific nations."

Pacific leaders have not just been ramping up pressure on Australia — Mr Bainimarama also criticised countries such as China and Russia for unveiling a 2060 net zero goal without giving specific plans to cut down emissions this decade. "We have fallen so far off-course that only bold and courageous action will suffice," he said.

"2060 is too late, empty promises of mid-century ambition are not enough.
"All high-emitting countries must halve global emissions by 2030."
He argued the future of some nations was at stake.

"We Pacific nations have not travelled to the other end of the world to watch our future to be sacrificed at the altar of appeasement of the world's worst emitters," Mr Bainimarama said.

"The existence of our low-lying neighbours is not on the negotiating table.

"Humanity does not lack the resources, technology, projects, innovative potential to achieve it — all that is missing, ladies and gentlemen, is the courage to act."

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(ABC News) David Attenborough Addresses World Leaders At COP26 In Glasgow, Saying Humans Are Powerful Enough To Address Climate Change

ABC News

Sir David Attenborough calls on leaders at COP26 to kickstart the recovery of the planet.

Key points
  • Sir David Attenborough warned that human actions were causing rising carbon levels in the atmosphere
  • He said humans also had the capacity to fix this, if they worked together
  • Sir David said the commitments made by world leaders at the Glasgow conference could have an effect
British naturalist and documentary maker Sir David Attenborough has issued a rallying cry to leaders at the United Nations Climate Change Conference in Glasgow, saying the world was looking to them to oversee the recovery of the planet.

Sir David, who was a "people's advocate" to the COP26 conference, said he had witnessed "a terrible decline" during his 95 years of life, but was confident that the next generation could and should see "a wonderful recovery".

"Our burning of fossil fuels, our destruction of nature, our approach to industry, construction and learning, are releasing carbon into the atmosphere at an unprecedented pace and scale," he told the conference.

"We are already in trouble."

He called on the world leaders to step up.

"It's easy to forget that ultimately the climate emergency comes down to a single number — the concentration of carbon in our atmosphere," Sir David said.

COP26 is our best chance
to stop global warming
On our current trajectory, we will heat the world by 1.5C in less than a decade, the United Nation's climate change panel has found. And if we don't act now, cooling the world will be increasingly hard. Read more
"The people alive now are the generation to come, [and] will look at this conference and consider one thing: Did that number stop rising and start to drop as a result of commitments made here? "There's every reason to believe that the answer can be yes."

Sir David also raised the issue of inequality, saying people in developing countries "who've done the least to cause this problem are being the hardest hit".

He said cooperation would be needed to tackle the issue.

"We are, after all, the greatest problem solvers to have ever existed on Earth," he said.

"If working apart, we are a force powerful enough to destabilise our planet. Surely working together, we are powerful enough to save it."

David Attenborough
COP26 transcript

As you spend the next two weeks debating, negotiating, persuading and compromising, as you surely must, it's easy to forget that ultimately the emergency climate comes down to a single number — the concentration of carbon in our atmosphere.

The measure that greatly determines global temperatures and the changes in that one number is the clearest way to chart our own story. For it defines our relationship with our world.

For much of humanity's ancient history, that number bounced wildly between 180 and 300 (parts per million). And so too, did global temperatures. It was a brutal and unpredictable world.

At times, our ancestors existed only in tiny numbers. But just over 10,000 years ago, that number suddenly stabilised and with it, Earth's climate.

We found ourselves in an unusually benign period with predictable seasons and reliable weather. For the first time, civilisation was possible and we wasted no time in taking advantage of that.

Everything we've achieved in the last 10,000 years was enabled by the stability in this time. The global temperature over this period has not wavered over this time by more than +/- 1 degree Celsius. Until now.

Our burning of fossil fuels, our destruction of nature, our approach to industry, construction and learning, are releasing carbon into the atmosphere at an unprecedented pace and scale. We are already in trouble.

The stability we all depend on is breaking. This story is one of inequality as well as instability.

Today, those who've done the least to cause this problem are being the hardest hit. Ultimately all of us will feel the impact, some of which are now unavoidable.

Is this how our story is due to end? A tale of the smartest species doomed by that all too-human characteristic of failing to see the bigger picture in pursuit of short-term goals.

Perhaps the fact the people most affected by climate change are not some imagined future generation, but young people alive today.

Perhaps that will give us the impetus we need to rewrite our story, to turn this tragedy into a triumph. We are, after all, the greatest problem solvers to have ever existed on Earth.

We now understand this problem, we know how to stop the number rising and put it in reverse.

We must halt carbon emissions this decade. We must recapture billions of tonnes of carbon from the air.

We must fix our sights of keeping 1.5 degrees in reach. A new industrial revolution powered by millions of sustainable innovations is essential and is indeed already beginning.

We will all share in the benefits of affordable clean energy, healthy air and enough food to sustain us all. Nature is a key ally, whenever we restore the wild it will recapture carbon and help us bring back balance to our planet.

As we work to build a better world, we must acknowledge no nation has completed its development because no advanced nation is yet sustainable.

All have a journey still to complete so all that nations have a good standard of living and a modest footprint.

We again have to learn together how to achieve this, ensuring none are left behind. We must use this opportunity to create a more equal world and our motivation should not be fear, but hope.

It comes down to this, the people alive now are the generation to come, will look at this conference and consider one thing: Did that number stop rising and start to drop as a result of commitments made here?

There's every reason to believe that the answer can be yes.

If working apart, we are a force powerful enough to destabilise our planet. Surely working together, we are powerful enough to save it. In my lifetime, I've witnessed a terrible decline.

In your lifetimes, you could and should witness a wonderful recovery. That desperate hope ladies and gentleman, delegates, excellencies, is why the world is looking to you and why you are here. Thank you.


What is COP26 and why should we care?

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