Saturday, 24 March 2018

Paul Ehrlich: 'Collapse Of Civilisation Is A Near Certainty Within Decades'

The Guardian

Fifty years after the publication of his controversial book The Population Bomb, biologist Paul Ehrlich warns overpopulation and overconsumption are driving us over the edge
The toxification of the planet with synthetic chemicals may be more dangerous to people and wildlife than climate change, says Ehrlich. Photograph: Linh Pham/Getty Images
A shattering collapse of civilisation is a “near certainty” in the next few decades due to humanity’s continuing destruction of the natural world that sustains all life on Earth, according to biologist Prof Paul Ehrlich.
In May, it will be 50 years since the eminent biologist published his most famous and controversial book, The Population Bomb. But Ehrlich remains as outspoken as ever.
Prof Paul Ehrlich of Stanford University.
Photograph: Alamy Stock Photo 
The world’s optimum population is less than two billion people – 5.6 billion fewer than on the planet today, he argues, and there is an increasing toxification of the entire planet by synthetic chemicals that may be more dangerous to people and wildlife than climate change.
Ehrlich also says an unprecedented redistribution of wealth is needed to end the over-consumption of resources, but “the rich who now run the global system – that hold the annual ‘world destroyer’ meetings in Davos – are unlikely to let it happen”.
The Population Bomb, written with his wife Anne Ehrlich in 1968, predicted “hundreds of millions of people are going to starve to death” in the 1970s – a fate that was avoided by the green revolution in intensive agriculture.
Many details and timings of events were wrong, Paul Ehrlich acknowledges today, but he says the book was correct overall.
“Population growth, along with over-consumption per capita, is driving civilisation over the edge: billions of people are now hungry or micronutrient malnourished, and climate disruption is killing people.”
Make modern contraception and back-up abortion available to all and give women full equal rights, pay and opportunities
Ehrlich has been at Stanford University since 1959 and is also president of the Millennium Alliance for Humanity and the Biosphere, which works “to reduce the threat of a shattering collapse of civilisation”.
“It is a near certainty in the next few decades, and the risk is increasing continually as long as perpetual growth of the human enterprise remains the goal of economic and political systems,” he says. “As I’ve said many times, ‘perpetual growth is the creed of the cancer cell’.”
It is the combination of high population and high consumption by the rich that is destroying the natural world, he says. Research published by Ehrlich and colleagues in 2017 concluded that this is driving a sixth mass extinction of biodiversity, upon which civilisation depends for clean air, water and food.
High consumption by the rich is destroying the natural world, says Ehrlich. Photograph: Paulo Whitaker/Reuters
The solutions are tough, he says. “To start, make modern contraception and back-up abortion available to all and give women full equal rights, pay and opportunities with men.
“I hope that would lead to a low enough total fertility rate that the needed shrinkage of population would follow. [But] it will take a very long time to humanely reduce total population to a size that is sustainable.”
It will take a very long time to humanely reduce total population to a size that is sustainable
He estimates an optimum global population size at roughly 1.5 to two billion, “But the longer humanity pursues business as usual, the smaller the sustainable society is likely to prove to be. We’re continuously harvesting the low-hanging fruit, for example by driving fisheries stocks to extinction.”
Ehrlich is also concerned about chemical pollution, which has already reached the most remote corners of the globe. “The evidence we have is that toxics reduce the intelligence of children, and members of the first heavily influenced generation are now adults.”
He treats this risk with characteristic dark humour: “The first empirical evidence we are dumbing down Homo sapiens were the Republican debates in the US 2016 presidential elections – and the resultant kakistocracy. On the other hand, toxification may solve the population problem, since sperm counts are plunging.”
Plastic pollution found in the most remote places on the planet show nowhere is safe from human impact. Photograph: Conor McDonnell 
Reflecting five decades after the publication of The Population Bomb (which he wanted to be titled Population, Resources, and Environment), he says: “No scientist would hold exactly the same views after a half century of further experience, but Anne and I are still proud of our book.” It helped start a worldwide debate on the impact of rising population that continues today, he says.
The book’s strength, Ehrlich says, is that it was short, direct and basically correct. “Its weaknesses were not enough on overconsumption and equity issues. It needed more on women’s rights, and explicit countering of racism – which I’ve spent much of my career and activism trying to counter.
“Too many rich people in the world is a major threat to the human future, and cultural and genetic diversity are great human resources.”
Accusations that the book lent support to racist attitudes to population control still hurt today, Ehrlich says. “Having been a co-inventor of the sit-in to desegregate restaurants in Lawrence, Kansas in the 1950s and having published books and articles on the biological ridiculousness of racism, those accusations continue to annoy me.”
But, he says: “You can’t let the possibility that ignorant people will interpret your ideas as racist keep you from discussing critical issues honestly.”

More of Paul and Anne Ehrlich’s reflections on their book are published in The Population Bomb Revisited.


Britain Blocks Plans For New Coal Mine On Climate Grounds

ReutersSusanna Twidale

LONDON - Britain has rejected plans for a new open cast coal mine in northeastern England, as it could hamper efforts to reduce greenhouse gas emissions and curb climate change, the minister for local government said on Friday.
A view of the slopes of the Banks Group Shotton open cast mine in Northumberland, Britain, November 11, 2016. Picture taken November 11, 2016. REUTERS/Barbara Lewis/File Photo
Supporters of the project had said it could bring much needed jobs to the region, while environmental campaigners said it would go against Britain’s commitment to reduce greenhouse gases.
Britain plans to phase-out coal use at its power stations by 2025 as a part of its efforts to meet its climate targets, and is part of an international alliance pushing other countries to do the same.
Northumberland County Council agreed last year that the mine’s developer The Banks Group could extract 3 million tonnes of coal by cutting an open cast, or surface mine, near Druridge Bay, Highthorn.
But local government minister Sajid Javid rejected the application on Friday following a public inquiry, government documents show.
“The scheme would have an adverse effect on greenhouse gas emissions and climate change of very substantial significance, which he gives very considerable weight in the planning balance,” the government report, rejecting the application said.
Gavin Styles, managing director at the mine’s developer Banks Mining, said Britain was still dependent on coal for a number of purposes and the decision had been taken for “purely political reasons.”
A digger at the Banks Group Shotton open cast coal mine in Northumberland, November 11, 2016. Picture taken November 11, 2016. REUTERS/Barbara Lewis/File Photo
“The importance of securing investment in North East England, creating dozens of high quality local jobs, and opening up opportunities for regional suppliers to win substantial contracts could not be any clearer,” he said in an emailed statement.
The company said the project could employ 100 people and generate almost 50 million pounds ($70.43 million) in related contracts and other benefits to the community.
Styles said the company would carefully review the decision before deciding on the most appropriate next steps to take.
Environmentalists had criticized the plans, saying it would destroy an area of natural beauty and that extracting more coal is at odds with international pledges to reduce greenhouse gas emissions under the Paris climate pact.
“This is the first coal mine ever to be rejected in the UK because of climate change impacts – a vindication for everyone who has been calling for fossil fuels to be left in the ground,” said Rose Dickinson, campaigner with environmental group Friends of the Earth.
Britain has a legally binding target to cut emissions of harmful greenhouse gases, such as those produced by fossil-fuel-based power plants, by 80 percent from 1990 levels by 2050.
It has also signed up to the international Paris agreement to curb emissions.


Coal Plant Construction Extends Dive - But Not Fast Enough: Report

Fairfax - Peter Hannam

Coal-fired power is on track to start shrinking globally by 2022, dimming prospects for exporters of the fossil fuel, including Australia, according to a report by environmental groups.
China and India, which have dominated construction of new power plants for more than a decade, both cut new capacity sharply for the second year in a row in 2017, the annual Boom and Bust report by Greenpeace, Sierra Club and CoalSwarm found.
On current trends, coal plant capacity worldwide could peak by 2022. Photo: AP
Taking into account plants that closed, China's net addition in 2017 was its lowest since 2003. For India, last year's newly operating capacity of 9 gigawatts was the smallest since 2009.
"China and India were once seen as countries blocking progress on climate change," Nikola Casule, a Greenpeace climate and energy campaigner, said. "That's clearly no longer the case."
By most measures, world approvals and construction of new coal-fired plants extended declines for a second year. Newly completed power stations were down 41 per cent compared with two years earlier to 60.2 GW, while construction starts were down 73 per cent to 45.9 GW, the report said.
With 97 GW of coal plants retiring in the past three years alone - almost half of that in the US - the world's coal fleet is on track to begin shrinking by 2022, it said.

Still, since coal plants typically have a design life of 40 years or more, the rates of retirements and cancelled projects both need to speed up if global carbon emission reduction targets are to be reached.
"In order to meet the goals of the 2015 Paris climate agreement, the current pace of progress must be accelerated, including cancelling coal power projects under development and hastening retirement of aging coal fleets in Europe and the United States," it said.
The global trends raise questions about the outlook for Australia's coal export markets, and the wisdom of government support to open up major new mines such as Adani's planned Carmichael project in Queensland's Galilee Basin, Dr Casule said.
"The worst thing you could do is to build one of the world's biggest coal mines," he said.
The Australian Financial Review this week reported Adani is refusing to set a funding deadline after admitting that it would fail to meet a set-imposed target for the end of this month.
Tumbling prices for renewable energy, particularly solar panels, combined with the global agreement to reduce carbon emissions, mean the challenges for the thermal industry will continue to mount.
Instead, it was incumbent on governments and industry to prepare coal-mining communities for their inevitable decline.
"It would be a betrayal of Australians if we didn't plan for that transition," Dr Casule said.
The NSW Minerals Council declined to comment. Earlier this month, the industry lobby group said exports of thermal coal used in power plants reached 140 million tonnes in 2017, slightly down on 2016 but 15 per cent higher than five years earlier.
Matt Canavan, federal resources minister, said coal would "continue to be an important power source for decades to come".
“The International Energy Agency predicts Asian coal demand will increase by almost 12 per cent from 2016 through to 2040," he said.
“The greater use of Australia's higher quality coal will help bring down emissions because Australian coal has more energy content and hence generates fewer emissions."
The mining industry has highlighted prospects for new coal-fired power in south-east Asia.
Indonesia has the most new coal power under construction after China and India, the report found. Still, even there support may be waning as projects get cancelled.

IMAGE   Link

Friday, 23 March 2018

Australia One Of The Countries Most Exposed To Climate Change, Bank Warns

Fairfax - Cole Latimer

Australia is one of the countries most vulnerable to climate change in the developed world, and the threat of Australians dying from global warming-related events has risen, global bank HSBC warns.
Australia is at risk of more bushfires as climate change continues. Photo: Jonathan Carroll
A new report by the bank, titled Fragile Planet, has ranked 67 countries for their exposure to climate change risks. Australia scored poorly, with the largest percentage rise in deaths attributable to climate change in the developed world.
Combining data from the World Bank and EM-DAT, the International Disaster Database which calculates economic damage estimates, HSBC said fatalities attributable to climate change-linked events such as stronger storms, floods, or heat-related incidents surged from 0.36 per cent of the population between 1997 and 2006 to 3.41 per cent between 2007 and 2016.
At the same time, the number of people impacted by climate change events surged from 3.25 to 15.25 per 1000 of the population.
Israel and the US were the only developed countries with a bigger share of the population impacted by climate change-related events such as floods, storms, hurricanes, and wildfires.
lobally, the World Health Organisation forecasts that around 250,000 additional deaths annually will be attributable to climate change.
HSBC developed the report as a tool for investors to provide in-depth information on countries' climate change risk profiles, on their energy issues, risks to business operations, supply and demand and logistics as well as their long-term sustainable development issues.
Australia was ranked as highly sensitive to the physical risks of climate change, with predictions of more storms, floods, rain and bushfires. New Zealand ranked as one the nations least exposed to those risks.

Hurting the economy
Late last year, Deutsche Bank also developed a tool to forecast where its investments across the globe may be impacted by natural disasters brought on by climate change.
The German bank's economic modelling estimated that if carbon emissions aren't reduced throughout this century, per capita GDP will be 23 per cent lower than it otherwise would be.
Principal Advisor at The Australia Institute, Mark Ogge, said Australia's industries and infrastructure, such as coastal based business, roads and rail, and both commercial residential assets, are at significant risk from climate change-related events.
"There's up to $236 billion of infrastructure at risk from a one-metre sea level rise alone," Mr Ogge said. Temperature increases also put Australia's tourism industry at risk, with a rising number of days above 35 degrees celsius in holiday destinations such as Far North Queensland, he added.
The Australia Institute believes billions of dollars in infrastructure are at risk from a one-metre sea level rise. Photo: Ashley Roach
Australia is the only developed market that ranked within the top ten in HSBC's report for energy transition issues due to its high levels of fossil fuel exports – particularly coal – and is one of the few countries that has seen these exports growing as a percentage of their gross domestic product.
HSBC sees risks to the nation's economy as Australia attempts to shift its energy and economic system, currently underpinned by fossil fuels, to one with a greater mix of renewables.
“Many countries and other actors are at risk of seeing parts of their old energy economy becoming effectively ‘stranded assets’ – or economically non-viable – given the relative economics of alternatives and new breakthrough technologies,” the HSBC report stated.
“Managing the transition to a lower carbon economy is key to mitigating downside risks," the bank said. "We think achieving diversification is key.”

The good news
However, it is not all bad news. Australia was ranked amongst the top three nations – along with New Zealand and Norway – with the greatest potential to respond to climate change and financially prepare the country for a changing environment.
Despite Australia’s frequent drought conditions, it was seen as a market with adequate water resources availability, while Singapore was the developed market most at risk over water availability.


Millions More Hungry In 2017 Amid Famine, Conflict, And Numbers Rising-Report

ReutersThin Lei Win

"We are clearly seeing a trend now, from 80 million to 108 million, from 108 to 124 million, people literally marching to the brink of starvation around the world"
An internally displaced woman sits with her severely acute malnourished children as they wait to receive medical attention at the Tshiamala general referral hospital of Mwene Ditu in Kasai Oriental Province in the Democratic Republic of Congo, March 15, 2018. Picture taken March 15, 2018. REUTERS/Thomas Mukoya
ROME - Conflicts and climate disasters, particularly drought, drove the number of people facing crisis levels of hunger up by about 15 percent last year and the situation is getting worse, a report said on Thursday.
Last year 124 million people in 51 countries faced crisis levels of hunger compared to 108 million people in 48 countries in 2016 and 80 million in 2015, according to the Food Security Information Network (FSIN).
The FSIN is a global project set up to strengthen food and nutrition security information systems that is sponsored by the United Nations' Food and Agriculture Organization (FAO), the World Food Programme and the International Food Policy Research Institute.
"We are clearly seeing a trend now, from 80 million to 108 million, from 108 to 124 million, people literally marching to the brink of starvation around the world," said David Beasley, WFP's executive director.
"We will never address the issues of the day until we end some of these conflicts," he added at the report's launch.
The FSIN report said the rising numbers in 2017 were largely due to new or intensified conflicts in Myanmar, north-east Nigeria, the Democratic Republic of Congo, South Sudan and Yemen.
In 2018, "conflict will remain a primary driver of food security", it said, while severe dry weather is expected to affect crop and livestock production and worsen hunger in many parts of Africa.
Yemen, where a proxy wdroughteport said.
It also singled out Eritrea, North Korea and Venezuela as places of concern but said a lack of data made it difficult to estimate the number of people left hungry.
The analysis showed the situation could worsen in 2018 in at least three or four countries, Luca Russo, senior food crises analyst at the FAO, told the Thomson Reuters Foundation.
The FSIN uses a five phase scale with the third level classified as crisis, fourth as emergency and fifth as famine/catastrophe.
"In South Sudan, we all applaud ourselves because we avoided famine last year, but the figures today tell us we might have famine in South Sudan in the next few months and this can also apply to other countries," Russo said.


Complex Science Behind Climate Change And Extreme Weather

ABC WeatherKate Doyle

Only a chimney is left standing in this Tathra house after Sunday's fire. (ABC News: Bianca Gurra)
As cyclone Marcus ripped through Darwin and fires burned homes to the ground in Victoria and New South Wales, it was just a matter of time until the climate change discussion reared its head.
This week the Greens drew a link between the two, with comments made in the Senate and in the media, saying that fires are now more severe and frequent because of climate change.
The Prime Minister Malcolm Turnbull later commented that he was reportedly "disappointed" the Greens would politicise the events.
"You can't attribute any particular event, whether it's a flood or fire or a drought or a storm — to climate change," he said while on a visit to Bega, near the bushfire-affected areas.
Two people who have protested Mr Turnbull's remarks are Dr Sarah Perkins-Kirkpatrick from the University of New South Wales and Dr Andrew King of the University of Melbourne.
They are two of Australia's leading researchers in climate change's role in extreme events and have spoken to the ABC regarding the field of 'climate change attribution'.

How does climate change attribution work?
The basic principle behind climate change attribution is comparing the world as it is, with how it would have been without human-induced greenhouse gasses.
To do this researchers use climate models which work like computer-based virtual worlds, to recreate the real world as closely as possible.
They then look at two sets of model experiments, one which is as close as possible to the current world, and one where the human introduced greenhouse gasses have been removed.
"We look at the frequency of that specific event between those two simulations and then compare how often it occurs now, compared to the natural world — as we think it used to be," said Dr Perkins-Kirkpatrick.
"Essentially what we're doing is looking between those two groups of models and how the probability or intensity of extreme weather events [such as] heat waves, heavy rainfall events and droughts, are changing just between those two ensembles," said Dr King.
In the past, these attribution studies have found a link between the Canberra and Sydney Heatwaves of February 2017 and climate change.
For more complex weather events, for example Cyclone Debbie, or the 2011 floods of south east Queensland, Dr King says "it's harder to tell."
Dr Sarah Perkins-Kirkpatrick spoke about climate change attribution at the AMOS conference in Sydney in February. (ABC Weather: Kate Doyle)
Part of the reason is that there is a lot of complexity in this analysis.
According to Dr Perkins-Kirkpatrick, "It's not that easy.
"A lot of time, a lot of blood, sweat and tears go into actually defining the event and making sure you've got it right.
"It's taken me weeks before to make sure I've captured the event as well as I can."
How the event is defined, the model used, which parameters are included and how the data is analysed statistically, can all change the outcome, so these simulations are often repeated many times to ensure a robust result.

What are the limitations?
Dr Perkins-Kirkpatrick said one of the limitations of climate change attribution studies is that they are heavily model-based.
"You have to be certain, or very confident at least, that that model is a good representation of the actual climate," she said.
"Unfortunately, however, no matter how good your model is, we simply can't really measure what the climate used to be like before climate change actually started."
There are some old observations, mainly in Europe, and paleo records, that are helping to improve knowledge in this area.
But our understanding of pre-industrial revolution conditions are not as good as our understanding of the current climate.
Dr Andrew King at the AMOS conference in Sydney 2018 (ABC Weather: Kate Doyle)
The type of event matters too.
Dr King said that hot or cold extremes are quite easy to attribute, especially on a big scale; other more variable events like rainfall, are more difficult.
"More complex events like fire weather, which has a combination of high temperatures, low humidity, strong winds — those are a lot harder."
Dr Perkins-Kirkpatrick also puts individual cyclones in the variable pile.
"It doesn't necessarily mean with those events that there is no anthropogenic signal," said Dr Perkins-Kirkpatrick.
"It just means that we can't yet detect it because there's a lot of variability overlying that particular signal."

'Weather' vs. 'climate'
Communicating the difference between long term-climate trends and individual extreme weather events is where all of this gets messy.
The weather is what is going on day-to-day; the climate is what is happening over time.
Using the wardrobe analogy: climate is all of the clothes in your closet, while weather is what you wear each day.
Which raises the question: does every event need to prove or disprove climate change?
According to Dr Perkins-Kirkpatrick the answer is no.
"A lot of the events — I'm just saying a lot, I'm not saying all on purpose — would have probably occurred without climate change, but now they're occurring more frequently," she said.
"And that's exactly what attribution looks at: whether or not a particular event is occurring more frequently because of climate change,.
"We've always had tropical cyclones for example, they're always going to occur.
"It doesn't necessarily mean that every single tropical cyclone needs to be attributed to climate change."
"And we look at every event separately because they're all very different and very individual."
Likewise, not every cold snap means climate change is wrong.
"It's quite frustrating as a climate scientist to hear people saying that," Dr King said. "Especially if it's the president of the United States, it's not very helpful."
"We're always going to have that variable weather — even in a hundred years.
"It's just that the warm extremes are a bit warmer, the cool extremes are not quite as cold as they would've been in the past."
The driver of this ute got a shock when a palm tree outside his house came crashing down on him during Cyclone Marcus on Saturday. (ABC News: Neda Vanovac)
Both Drs King and Perkins-Kirkpatrick are trying to move away from publicly assigning a number or percentage to how much climate change has contributed to an individual event, despite media pressure.
Dr Perkins-Kirkpatrick said she understands the pressure from the media, "They want that analysis because it is interesting and it does show that climate change is actually happening now."
The researchers explain there is only so fast they can get such analysis done.
"We're reasonably confident in the method, but sometimes the media wants these results yesterday," Dr Perkins-Kirkpatrick said.
A fully quantifiable scientific analysis takes time.
"When we do put a number on it, it's not necessarily one that we've plucked out of thin air," Dr Perkins-Kirkpatrick said
"We've looked at the event, we've repeated the analysis thousands of times, so we have a range, and we never give the number that's the most scary, or the highest number — we give a very conservative number."
"So even if we say an event is, for example, twice as likely due to climate change, that's probably the lower estimate."
For Dr King, it is about making sure the context is there.
"We always give uncertainties with those numbers but often it's lost in the communication from the media sources to the public," he said.
Flames come close to a home in Tathra as a large bushfires burnt through the town on Sunday 18 March, 2018. (ABC News: Peta Doherty)
So last weekend's events?
Last weekend's fires and cyclone may have been later than most but they still occurred within both the official NSW Rural Fire Services Bush Fire Danger Period and the NT's cyclone season.

With all of this confusion, is climate change attribution useful?
Darwin residents have a lot of work ahead of them, to recover from Tropical Cyclone Marcus. (ABC News: Emma Vincent)
Dr King said it was the extreme events that people remembered.
"Understanding how [extreme weather events] are changing resonates with people I think," he said.
"So it's a really good communication tool."
Dr Perkins-Kirkpatrick said that ultimately, it is useful.
"Especially if you have all your methods pointing towards yes," she said. "You can say with confidence — with high confidence — that there's a signal there."
"Conversely, certain events you can't necessarily attribute to climate change.
"And if all your methods say the same thing, that climate change did not affect this event, you can say that with confidence as well."


Thursday, 22 March 2018

Court As Class: Judge Gets Climate Change Lesson In Oil Suit

ABC America - Sudhin Thanawala, Associated Press

EPA Chief Scott Pruitt still won't say if President Trump believes climate change is a hoax

There were no test tubes or Bunsen burners, but a courtroom turned into a science classroom Wednesday for a U.S. judge considering lawsuits that accuse big oil companies of lying about the role of fossil fuels in the Earth's warming environment.
Leading researchers taught U.S. District Judge William Alsup the basic science of climate change at the unusual court hearing after he asked lawyers for two California cities and five of the world's largest oil and gas companies to present "the best science now available on global warming."
He cautioned at the start of the hearing against expecting "fireworks" and said he wanted to avoid politics and "stick to the science."
"This is a serious proposition to try to educate the judge," Alsup said.
What he got at the end of the nearly five-hour hearing was a primer on the history of climate change research, carbon dioxide's role as a greenhouse gas, melting ice caps, rising sea levels and extreme weather.
His teachers included Myles Allen, a professor at the University of Oxford who studies human influences on climate, and Don Wuebbles, an expert in atmospheric science at the University of Illinois who co-authored a 2017 U.S. government report on climate change.
An attorney for Chevron, Theodore Boutrous, also presented, saying the oil giant does not dispute the findings of an international panel of scientists that it is extremely likely people are the dominant cause of global warming since the mid-1900s.
But he pointed out how thinking about global warming has evolved and said the company does not agree with all proposals in place to deal with it.
"The notion that we know today of a dynamic changing climate is relatively new in human understanding," he said.
Alsup interrupted Boutrous and the scientists to ask about the climate on Mars, what caused the ice age and whether the ozone layer has a role in the warming and cooling of the planet, among other questions.
He is considering two lawsuits, one by San Francisco and the other by neighboring Oakland, that accuse Chevron, Exxon Mobil, ConocoPhillips, BP and Royal Dutch Shell of long knowing that fossil fuels posed serious risks to the climate, but still promoting them as environmentally responsible. They also allege the companies mounted campaigns to downplay the risks of global warming and discredit research that human activity was to blame.
The companies have asked the judge to dismiss the lawsuits. Federal law controls fossil fuel production, and Congress has encouraged oil and gas development, they said in court documents. They say the harm the cities claim is "speculative" and part of a complex chain of events that includes billions of oil and gas users and "environmental phenomena occurring worldwide over many decades."
Legal observers said they had never heard of a court holding a tutorial on climate change, and they were eager to see how the oil companies explained global warming.
None of the other companies spoke. Alsup told their attorneys that he wanted them to file documents indicating whether they disagreed with what Chevron's attorney said.
"You can't get away with sitting there in silence and later say he wasn't speaking for us," the judge said.
The lawsuits say the companies have created a public nuisance and should pay for sea walls and other infrastructure to protect against the effects of climate change — construction that could cost billions of dollars.
New York City, several California counties and at least one other California city have filed similar suits.
San Francisco City Attorney Dennis Herrera said the hearing showed the science on climate change was "clear."

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