Sen. Bernie Sanders (I-Vt.) seems to be losing steam — and doubling down on what he knows best to regain it.

On Wednesday, Sanders gave a lengthy speech outlining what he means when he says he's a "democratic socialist." It was chock full of historical references and mentions of President Trump, but, as some Sanders supporters and Democratic strategists suggest, may have been more aimed at Sen. Elizabeth Warren (D-Mass.).

Sanders and Warren are often seen as progressive equivalents, except for when Warren declares herself a capitalist and Sanders sticks to socialism. Despite that ideological difference, Warren has seemingly been the only Democratic presidential candidate gaining steam over the past few weeks, and it has largely come at Sanders' expense. In fact, an Economist/YouGov poll released just an hour before Sanders' Wednesday speech showed Warren had 19 percent support in the 2020 race over Sanders' 15 percent. Sanders had been at a solid second place to former Vice President Joe Biden before that.

This the first major poll where Warren has managed to pass Sanders, and to Democratic strategist and former White House Communications Director Jen Psaki, it's just what Sanders was worried about. His Wednesday speech "is a pretty clear indication he is feeling the heat from Elizabeth Warren's recent momentum among progressive voters," Psaki told The New York Times, calling it Sanders' "attempt to reclaim the anticapitalist mantle he ran on in 2016."

Even before Wednesday's poll debuted, it didn't seem Warren was too worried about whatever socialist rhetoric Sanders had cooked up. When The Atlantic asked her about Sanders' forthcoming speech the other day, she laughed. Kathryn Krawczyk

University of Oxford scientists have reportedly developed the first malaria vaccine which, in a trial, surpassed a key goal of greater than 75 percent efficacy.

In a trial consisting of 450 children in Burkina Faso between the ages of five and 17 months, this vaccine candidate was shown to be 77 percent effective against malaria, Bloomberg reports. It also showed a "favorable safety profile and was well-tolerated." The study was published in The Lancet, though it has not yet been peer-reviewed, and the vaccine is set to be studied further in larger clinical trials with 4,800 children in four African countries.

But Bloomberg noted it was the first vaccine against malaria to show greater than 75 percent efficacy, the World Health Organization goal for such a vaccine. According to BBC News, the most effective malaria vaccine to this point showed 55 percent efficacy in trials with African children. There were an estimated 409,000 malaria deaths and 229 million cases worldwide in 2019, the World Health Organization says.

"An effective and safe malaria vaccine would be a hugely significant extra weapon in the armory needed to defeat malaria," Malaria No More U.K.'s Gareth Jenkins said. "Countries freed from the malaria burden will be much better equipped to fight off new disease threats when they inevitably emerge in the future."

Adrian Hill, director of the University of Oxford's Jenner Institute, also told BBC News that the trial suggests this vaccine "has the potential to have a major public health impact." Brendan Morrow

India on Friday reported 332,730 new COVID-19 cases from the past 24 hours, beating the grim record it set Thursday, and oxygen supplies in the country are so low that several hospitals in the capital, New Delhi, said they have nearly or completely exhausted their supplies. As hospital put out emergency calls for oxygen on social media, the government is scrambling to ship in reserves from retooled industrial oxygen plants. Meanwhile, COVID-19 patients are dying while their families search for open hospital beds, and crematoriums cannot keep up with demand.

India on Friday reported 2,263 new deaths over the past 24 hours, for a total pandemic fatality count of 186,920, but "those who've analyzed the numbers of daily cremations taking place suggest the number is many times higher," Aleem Maqbool reports at BBC News.

An analysis Thursday by the Financial Times found that the number of COVID-19 cremations in four Indian states was anywhere from three times the official number of COVID-19 deaths in some districts to 100 times higher in others. "Local news reports for seven districts across the states of Gujarat, Uttar Pradesh, Madhya Pradesh, and Bihar show that while at least 1,833 people are known to have died of COVID-19 in recent days, based mainly on cremations, only 228 have been officially reported," FT says.

Health experts blame India's COVID-19 tsunami on more transmissible new variants, especially the B.1.617 strain first detected in the country last month, plus a lack of preparation for a coronavirus resurgence and decisions by Indian Prime Minister Narendra Modi's Hindu nationalist BJP party to permit mass Hindu religious gatherings and hold packed BJP rallies for upcoming elections in West Bengal state.

Vijay Chauthaiwale, a BJP official who heads India's foreign affairs department, told BBC News there's no proof the rallies and Hindu festivals were super-spreader events and blamed the rise in cases on individuals deciding to stop social distancing and mask-wearing, and start using public transportation. But BJP isn't above politicizing the pandemic.

"The entire system has broken down," Santosh Kumar, the son of a BJP leader in Lucknow, told FT. "Every other person in the administration here is quarantining. People are finding out from each other what medication to take and doing what they can." Peter Weber

President Biden on Thursday nominated longtime environmental advocate Tracy Stone-Manning to head the Bureau of Land Management, the Interior Department division that oversees about a quarter-billion acres of federal lands in Western states. BLM also manages drilling and mining rights, animal grazing, and recreational activities on those lands.

Stone-Manning, 55, has worked at the National Wildlife Federation since 2015, and before that she led Montana's Department of Environmental Quality and worked as chief of staff to former Gov. Steve Bullock (D) and an aide to Sen. Jon Tester (D-Mont.). Tester said in a statement that Stone-Manning is "a tireless public lands champion with a lifetime of experience," while Montana's other senator, Steve Daines (R), said he would be "digging through and looking at her record and history" on environmental and energy issues.

BLM never had a Senate-confirmed director under former President Donald Trump, who cycled through "a string of acting directors to execute a loosening of restrictions on industry," The Associated Press reports. "Chief among them was conservative lawyer William Perry Pendley, who before he took the position advocated for selling off federal lands." After Pendley stayed in the job for more than a year without a Senate hearing, Bullock — with Stone-Manning's support — sued, and a federal judge ordered Pendley removed.

Montana Petroleum Association director Alan Olson said Stone-Manning, who he served on a climate council with, is highly intelligent, "left of center" but not extreme, and receptive to opposing arguments, but she should expect from Republicans the same treatment Democrats afforded Trump's appointees. "Tracy went after Pendley," he told AP. "She can expect the same." Peter Weber

"Happy Earth Day," Jimmy Fallon said on Thursday's Tonight Show. "Everyone's in the spirit. This morning at 7-Eleven I saw a rat drinking a Big Gulp with a metal straw," and "Subway recycled last week's tuna."

"President Biden hosted 40 world leaders for a virtual climate change summit," Fallon said. "With any virtual event, you're gonna have some technical glitches, but I didn't think it'd be quite this bad," he added. "Somehow we just flew a helicopter on Mars but we still can't get a Zoom meeting to work. Next time every leader will be required to have at least one grandchild present. It's funny that we were watching Putin and he didn't know he was on camera, because usually it's the other way around. "

"Humans celebrating Earth Day is like fleas celebrating Dog Day," Jimmy Kimmel joked at Kimmel Live. "There's actually something to celebrate today, though," because Biden "announced that the Unites States will cut our carbon emissions in half by the year 2030 — which is huge, because the science is absolutely clear that it's necessary to avoid a worldwide catastrophe. No one should be against this, so naturally almost every Republican is against this."

Biden's ambitious climate plan "can be met only by sharply cutting back oil, gas, and coal use," Stephen Colbert said at The Late Show. "That's gonna be rough on Santa. 'Ho ho ho, Katie! You've been naughty but coal's canceled, so here's the Snyder cut of Cats.'" Meanwhile on Mars, NASA's Perseverance rover just successfully turned carbon dioxide into oxygen, he noted. Because "when you think of planets in desperate need of a way to deal with excess carbon dioxide on Earth Day, you think Mars."

"Rough day for Earth Day, for the planet," James Corden said at The Late Late Show. "We've been giving so much attention to Mars recently, I'd really like it if we all just spend these next couple of days just really making it special for Earth." During Biden's virtual summit, "Vladimir Putin was adamant we cannot keep killing the planet — only journalists and political rivals. Not everyone was thrilled about the summit, though," he said. "Earlier today, climate activists dumped over a dozen wheelbarrows of cow poop in front of the White House to protest Biden's climate plan as bulls--t. ... Subtle."

Corden and Kimmel dryly reminded everyone the Oscars are Sunday, and The Late Show created a mock cinematic preview. Watch below. Peter Weber

Where most people saw an empty field at Satilla Marsh Elementary School in Brunswick, Georgia, four students instead envisioned a beautiful, tree-filled space — so they got to work and are making their forest come to life.

The fourth graders — Boston Riley, Griffin Goldstone, Abbott Johnson, and Tanner Lochstampfor — launched Green Leaves, a club that is not only planting trees on campus, but also promoting global reforestation. They have partnered with Forest Nation, and are planning a fundraiser later this year to sell trees for local residents to buy and then plant at home. For every tree sold, another will be planted in Tanzania.

"We were thinking how many trees get chopped down in this community," Riley told The Brunswick News. "So we were thinking it couldn't just be a school thing. We could just make it the whole community."

Using materials from Forest Nation, the students are learning about the importance of reforestation, and how it leads to cleaner air and creates jobs. They also intend on donating 25 percent of the proceeds from their fundraiser to the Glynn Environment Coalition, a gift that its executive director, Rachael Thompson, is excited to receive. "Youth are our future, and the fact that these young men have come out and decided to actually take an action to do something to better our environment and support or organization, that's kind of just a plus," she told The Brunswick News. Catherine Garcia

"Earth Day is the one day every year when you can't avoid news about the climate," but stories about world leaders pledging to cut emission targets are "pretty dull" for most Earthlings, Politico's Michael Grunwald wrote Thursday. Worse, they "don't usually make us think about how we live or what we drive or whether our species can survive on the only planet with pizza and breathable air and decent Wi-Fi, which is what the climate issue is really about."

MSNBC's Chris Hayes had some climate change–related news Thursday night, but it wasn't dry

California, land of perpetual water shortages, has "tried a million different ways around the problem," Hayes said, "but now Los Angeles has come up with a pretty brilliant and innovative solution to that city's water crisis — with an interesting wrinkle." Los Angeles buys most its water from the Colorado River in Arizona, but that river is drying up due to climate change, so L.A. is looking for a Plan B. Jacob Soboroff, on Earth Day, reported on the city's big bet: Recycled wastewater.

Los Angeles dumps 225 million gallons of treated wastewater into the Pacific every day, Soboroff said. "Now L.A. engineers and scientists are working on an ambitious plan to, by 2035, turn L.A.'s wastewater into L.A. drinking water." Los Angeles wouldn't be the first city to recycle wastewater — Wichita Falls, Texas, gave it a go in 2014 and 2015 — but it would be the largest. L.A. already has a pilot program "using very advanced technology" to redirect "toilets to taps" (or "showers to flowers," as Mayor Eric Garcetti likes to call it), Soboroff noted, and the city gave him — and Hayes — samples of this very clean water to try.

They drank it, for home and science. "We don’t have to freak out every day as if our home were on fire," Grunwald writes, "but Earth Day is a good day to remember that it is." Peter Weber