CLIMATE

PLANET WATCH--Scientists in the US have identified the factors that make a tree more likely to perish in a drought, after conducting an exhaustive examination of 33 separate scientific studies of tree mortality involving 475 species and 760,000 individual trees. (Photo above: Around 12 million trees have perished in California in the last year. Credit: NoIdentity via Flickr)

The answer they come up with is that the deciding factor is how efficiently trees draw water from the ground to their leaf tips.

This is not a surprising conclusion, but scientists don’t trust the obvious: they like to check these things.

And William Anderegg, assistant professor of biology at the University of Utah, and colleagues report in the Proceedings of the National Academy of Sciences on a list of 10 tree traits that could play a role in survival or death by drought. These include simple differences such as deciduous or evergreen, rooting depth, wood density, leaf characteristics.

Adapt and survive

Such research matters. In 2002 in the southwestern US, 225 million trees died where they stood because of drought. Texas alone lost 300 million trees in 2011. In California in the last year, 12 million trees have perished.

With losses on this scale, and more drought and heat extremes in store as climates begin to change because fossil fuel combustion worldwide has increased the levels of atmospheric greenhouse gases, foresters and conservationists need to know which species are most likely to adapt and survive, and what these species have that others do not.

In fact, deciding factors centre on the ability of a tree to draw water through the piping in its tissues. The forest giants may have to pump 200 litres of water every hour at a speed of 50 metres an hour to the topmost leaves, at a pressure of 30 atmospheres. 

And the process is at risk of interruption during drought by air bubbles. To put it heartlessly, trees, like humans, can perish from embolism.

“It’s a little bit akin to a tree heart attack,” Dr Anderegg says. “You can actually hear this on a hot summer day if you stick a microphone up a tree. You can hear little pings and pops as these pipes get filled with air.”

Those species already adapted to dry climates seem to be less at risk, while those that normally flourish in wetlands are more vulnerable to drought. So far, so obvious. But not all forest physiology is so obvious.

Forest cycle

Late last year, Dr Anderegg and his fellow researchers established that it was the increasing heat of the tropic night that was most likely to change tropical forests into carbon sources, rather than carbon sinks. What mattered was not global warming of itself, but how the warming was distributed through the forest’s diurnal cycle.

And since the world’s forests fulfil a vital role as carbon sinks—sequestering 2.4 billion tons of the greenhouse gas carbon dioxide every year, which is at least a quarter of all the carbon dioxide emissions from factory chimneys, motor exhausts and other human economic activity—what happens to forests as the world warms is vital for humankind as well. 

But global warming is also increasing the risk of forest loss by drought and wildfires.

“These widespread tree die-offs are a really early and visible sign of climate change already affecting our landscapes,” Dr Anderegg says.

(Tim Radford, a founding editor of Climate News Network) … where this column first appeared … worked for The Guardian for 32 years, for most of that time as science editor. He has been covering climate change since 1988.)

PLANET WATCH--If Xiuhtezcatl Tonatiuh didn’t have the look and sound of a 15-year-old, one could easily assume he was twice his real age. The indigenous environmentalist talks like a seasoned activist and well-educated adult, rather than the teenager he really is. Perhaps it is because he is so driven by passion for his cause of climate justice.

In an interview on Rising Up With Sonali, Tonatiuh revealed that he started his political activism at age 6. He explained that it was natural for climate change to be the cause dearest to his heart because “being involved in the climate movement is protecting everything that I love.” 

Tonatiuh, who is the youth director of Earth Guardians, is one of 21 young Americans who, together with former NASA scientist James Hansen, are bringing a lawsuit against the U.S. government for failing to curb climate change. A federal district court judge in Oregon recently cleared the way for the lawsuit with a ruling that affirmed the group’s legal right to sue the government. The lead plaintiff, 19-year-old Kelsey Juliana, released a statement saying, “This will be the trial of the century that will determine if we have a right to a livable future, or if corporate power will continue to deny our rights for the sake of their own wealth.”

Tonatiuh explained how the context of climate activism has changed over the years and led up to this legal effort. “When I first got up on stage [at age 6] and participated in rallies and protests, it was all old, white people. And now we’re seeing a change in this movement: more young people, more people of color,” he said. “With diversity in participants comes diversity in tactics. We have to be creative, innovative. Young people suing our government over climate change—that’s unheard of.”

At the heart of the lawsuit is the assertion that the government is violating the constitutional rights of young people by not doing all it can to stave off climate disaster. The recent record-breaking rains in Houston, leading to deadly floods that have claimed half a dozen lives, are only the latest indication of the reality of climate change.

Tonatiuh views the government’s priorities as seriously distorted, saying, “We have messed-up values at such a systemic level that we justify the destruction of our planet with a paycheck. We justify threatening our children’s future with the amount of money in our pockets.”

He’s right. Setting aside climate skeptics, most of our leaders in government and finance who acknowledge the role of humans in warming the planet reason that it would cost too much money to transition away from fossil fuels immediately. Tonatiuh, who is wise beyond his years, dismisses this destructive pragmatism with a quick retort: “If we subsidize renewable energies the way we do fossil fuels, we can power the world.”

Tonatiuh takes a nuanced view of President Obama, saying, “It’s tough in American politics because our Congress blocks so much action. [Obama] did some really great things while he was in office,” but, he added, “I really do believe he could have done more. He could have done less to push fossil fuels. An ideal leader would have done more than Obama did.”

Obama has been a mixed bag on climate change. His most notable achievements include refusing to approve the building of the Keystone XL pipeline and accepting the recent historic United Nations accord on climate change (however toothless the Paris Accord is). But perhaps his greatest feat has been to simply insist that climate change is a reality, particularly given the persistent intransigence of conservative and corporate-sponsored officials espousing climate denial. Tonatiuh had harsh words for climate denialists: “Politicians in greedy First World countries like the United States ... [who] deny climate change—they’re turning their back on every single life that has been lost, every single community that has been devastated.”

Whoever occupies the White House after Obama will do so at the most crucial juncture in the movement to save the planet from climate change. And yet the issue that is the underlying existential crisis of our time has hardly come up during the presidential debates and election-related media coverage over the past year. This compilation by the League of Conservation Voters reveals the depressing reality of the ludicrous views of Republican candidates Ted Cruz and Donald Trump. But even the Democrats are disappointing, with Hillary Clinton espousing a list of moderate reforms and Bernie Sanders failing to offer specific ideas despite his bold rhetoric. “All my chips are on a leader that will fight for our future,” said Tonatiuh, who recognizes the importance of tackling climate change in the next decade.

But Tonatiuh himself represents exactly the kind of leader our society desperately needs. In addition to his extensive political activism, he is also a musician. In his song “Indigenous Roots,” he raps, “We are part of the earth, not separate from it. We are the warriors of the land, the protectors of nature, and the guardians of the earth.” He calls himself a “conscious hip-hop artist,” which means that “everything I put out is with an intention to tell a story about what is happening in the world, to say something that matters.”

Tonatiuh is very conscious of his own community’s background. “My entire childhood I grew up learning about the genocide of my people, the oppression, the stealing of our land, our language, our culture,” he said. He is one of a growing number of indigenous activists all over the world who are on the front lines of the fight to beat back climate change. Groups like the Indigenous Environmental Network, the Global Justice Ecology Project and Tonatiuh’s organization, Earth Guardians, are leading movements across North America and the world.

Our world has failed young people like Tonatiuh. We have carried on with business as usual while burning away our children’s future. While this individual, inspiring teen has devoted his life to protecting the planet, why are the rest of us resting on our laurels?

(Sonali Kolhatkar is Co-Director of the Afghan Women's Mission and a political writer for TruthDig …where this piece was first posted.)

-cw

EDITOR’S PICK--California’s suburban sprawl has made the state’s transportation sector its largest single contributor to greenhouse gas emissions. With an expected addition of 6 million new residents in the next 15 years, whether California succeeds in building cities inward instead of outward could make all the difference in meeting its 2030 climate target, which calls for reducing greenhouse gas emissions 40 percent below 1990 levels by 2030.

PLANET WATCH--Enough of dealing with plastic trash once it floats down storm drains and rivers to end up on beaches, let's stop the plastic deluge upstream - especially the disposable single-use kind.

WATER POLITICS--There is no public service used more often or more reflexively than drinking water. Every time we reach for the faucet handle, without even thinking about it, we expect clean, drinkable water to pour out. Sadly, this ritual has been betrayed for years by big corporations and lax oversight, right here in California -- with very little public attention or outrage. 

Every year, Green Car Reports picks a new car or model line that we feel is the best green car for that new model year.  This year, we picked a car that's the all-new version of one that was revolutionary when it was introduced several years ago. The latest version improves on it in pretty much every dimension.

Redeem is a renewable biofuel that is cheaper than gasoline, and burns 90 percent cleaner.

An innovative new fuel is now available here in Southern California.  It’s clean, cheap, and made from an unlikely source -- trash.

ACTION ALERT--Greenbuild International Conference & Expo, the largest green building expo, comes to Los Angeles for the first time, on Oct. 5-7, 2016.  To that end, the first opportunity to get involved is the Legacy Project.  

CLIMATE CHANGE POLITICS-As the United Nations conference on climate change or COP21 came to an end, one of the main issues that needed to be addressed remained conspicuously absent from consideration by world leaders: controlling a world population that is rapidly approaching 7.5 billion people – this, on a planet whose optimum human population is estimated to be somewhere between 1.5 and 2 billion people. 

SPORTS POLITICS--Kareem Abdul-Jabbar has never been afraid to be unpopular if it meant taking a stand for what he believed in -- even if his legacy in the history books was at stake. This past week, he expressed sadness and just a hint of judgment when he said the greatest basketball player of all time, Michael Jordan, doesn’t share those same priorities. 

VOICES-The prolific Victor Davis Hanson wrote an excellent piece for National Review two weeks ago, in which he attributed California’s present middle-class stagnation and decline in economic opportunity to the devolution of California’s two-party system in the 90s and the Golden State’s emergence as a de facto one-party Democratic state. Hanson describes how a favorite Democratic policy inexorably led to the decline of the Republican voter base:

BLOG SOUP--Kevin Drum says people really aren't engulfed in existential despair after all: 

RACE IN AMERICA-Now former University of Missouri president Tim Wolfe (photo left) in a moment of rare candor for someone who just fired himself admitted what has been probably one of the worst kept secrets at American colleges. His words: “Racism does exist at our university, and it is unacceptable.” 

CALL TO ACTION--Eva Moskowitz’s Success Academy Charter School (photo) were recently exposed for having a “Got to Go” list of students, which singles out the children they would like to see leave through suspensions, counseling-out, or by not sending annual re-enrollment forms.