Joe Biden has upgraded his climate change plan. After consultation with Sen. Bernie Sanders and his progressive allies, the Biden campaign agreed to a compromise program that would be considerably faster and bigger than what he had previously called for. His plan would "mobilize millions of jobs by building sustainable infrastructure and an equitable clean energy future," he said in a speech Tuesday afternoon.

On one level, it is an encouraging development. Biden's plan, if implemented, would be orders of magnitude more significant than anything the Obama administration did. And as Eric Levitz writes at New York, now that Biden has sewn up the Democratic primary he is moving to the left on climate rather than to the right. However, there is still little sign that Biden or the rest of the Democratic establishment have fully grasped the colossal scale of the challenge that climate change poses. They are moving in the right direction, but they still have a long way to go.

First, the good. Biden has increased his proposed green investment from $1.7 trillion to $2 trillion. More importantly, he has accelerated the time frame — moving from a 10-year window to just four years. That, no doubt, is a recognition of the fact that the economy will still be in terrible shape in January should he take office. If the pandemic can be contained, then the U.S. will need an enormous fiscal stimulus to recover to full employment and production. That should unquestionably come in the form of green investment to cut greenhouse emissions.

Biden has also moved up his targets. Instead of aiming for a zero-emission economy in 2050, he now proposes to completely decarbonize electricity production by 2035. He would provide funds for an expansion of public transit in all cities with 100,000 or more residents, efficiency upgrades for 4 million buildings and 2 million homes, 1.5 million new efficient homes and public housing, subsidies for electric car production, and $400 billion for green technology research. The plan also includes some welcome social justice elements. Biden would direct 40 percent of the investment into disadvantaged communities, and would stand up a "climate conservation corps" to provide jobs cutting emissions and protecting the environment.

If actually passed — a tall order indeed, though at least Biden recently acknowledged it may be necessary to get rid of the Senate filibuster, which is a precondition for passing virtually anything — this would be a gigantic upgrade on President Obama's horrible climate record. Obama implemented some regulations on vehicle efficiency and power plant emissions, and provided some subsidies for green power, but he also ushered in a fracking boom that made the U.S. the biggest producer of oil and gas on the planet. We've "built enough pipeline to wrap around the entire earth once," Obama boasted during a presidential debate with Mitt Romney in 2012. In effect, Biden's plan would be undoing much of the damage he participated in as vice president.

The primary issue, however, is that Biden's concrete goals are still well short of the mark. Zeroing out electricity emissions by 2035 is a decently aggressive idea, but still probably slower than would be necessary to head off the worst climate futures. Upgrading building insulation is good, but his plan would still leave out most of the U.S. housing stock. Subsidizing electric cars is fine in itself, but as I have written e-bikes are much more promising — which would require a revolution in city planning to accommodate them. Biden also wouldn't ban fracking, which will be necessary over the medium term to keep carbon in the ground. Bernie Sanders' climate plan, by contrast, proposed $16.3 trillion in spending over 10 years, and aimed for zero net emissions in electricity and transportation by 2030.

Biden also has little to say about industry or agriculture. Unlike electricity production, there are no zero-carbon replacement processes for steel, concrete, or farming that are already ready to be deployed at scale. (Some are in the development stage, and to be fair, presumably much of the $400 billion in research would go towards accelerating these processes.)

Perhaps the biggest missing piece in Biden's plan is the international element. Climate change is an inherently international problem — the U.S. only emits about 13 percent of total greenhouse emissions, while China alone accounts for about 26 percent. The two major objectives of global climate policy must be somehow coaxing China into slashing its emissions and, at the same time, preventing the developing world (above all India) from following in its carbon-spewing footsteps. As Jacob Fawcett writes for the People's Policy Project, this will require a very large international investment fund to prevent poorer nations from building out the cheapest carbon-based power. As the richest big nation, by rights the U.S. should contribute the largest share of any such fund. This would be an act of generosity, but also a national security strategy to protect the American climate from uncontrolled warming. But again unlike Sanders, Biden has no plan to offer international climate aid.

Biden does promise a renewed effort at climate diplomacy. What that would mean is unclear, but at the least a Biden administration that held to its commitments would stop being an active hindrance to global climate politics. There has been a significant international movement building up behind climate policy over the years, but America has been a giant obstacle to coordination — under Trump the U.S. is literally the only country on the planet that refuses to sign on to the Paris climate accords.

Biden has boasted, questionably, that he helped usher China into the Paris agreement. Should he win the election in November, he will have the opportunity to forge some real climate accomplishments. It remains to be seen if he is up to the challenge.