This article is from The Spark, MIT Technology Reviews weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.Well, what about China?This is a comment I get all the time on the topic of climate change, both in conversations and on whatever social media site is currently en vogue. Usually, it comes in response to some statement about how the US and Europe are addressing the issue (or how they need to be).Sometimes I think people ask this in bad faith. Its a rhetorical way to throw up your hands, imply that the US and Europe arent the real problem, and essentially say: if they arent taking responsibility, why should we? However, amid the playground-esque finger-pointing there are some undeniable facts: China emits more greenhouse gases than any other country, by far. Its one of the worlds most populous countries and a climate-tech powerhouse, and its economy is still developing.With many complicated factors at play, how should we think about the countrys role in addressing climate change?Chinas emissions are the highest in the world, topping 12 billion tons of carbon dioxide in 2023, according to the International Energy Agency.Theres context missing if we just look at that one number, as I wrote in my latest story that digs into recent global climate data. Since carbon dioxide hangs around in the atmosphere for centuries, we should arguably consider not just a countrys current emissions, but everything its produced over time. If we do that, the US still takes the crown for the worlds biggest climate polluter.However, China is now in second place, according to a new analysis from Carbon Brief released this week. In 2023, the country exceeded the EUs 27 member states in historical emissions for the first time.This reflects a wider trend that were seeing around the world: Developing nations are starting to account for a larger fraction of emissions than they used to. In 1992, when countries agreed to the UN climate convention, industrialized countries (a category called Annex I) made up about one-fifth of the worlds population but were responsible for a whopping 61% of historical emissions. By the end of 2024, though, those countries share of global historical emissions will fall to 52%, and it is expected to keep ticking down.China, like all nations, will need to slash its emissions for the world to meet global climate goals. One crucial point here is that while its emissions are still huge, there are signs that the nation is making some progress.Chinas carbon dioxides emissions are set to fall in 2024 because of record growth in low-carbon energy sources. That decline is projected to continue under the countrys current policy settings, according to an October report from the IEA. Chinas oil demand could soon peak and start to fall, largely because its seeing such a huge uptake of electric vehicles.One growing question: With all this progress and a quickly growing economy, should we be expecting China to do more than just make progress on its own emissions?As I wrote in the newsletter last week, the current talks at COP29 (the UN climate conference) are focused on setting a new, more aggressive global climate finance goal to help developing nations address climate change. China isnt part of the group of countries that are required to pay into this pot of money, but some are calling for that to change given that it is the worlds biggest polluter.One interesting point hereChina already contributes billions of dollars in climate financing each year to developing countries, according to research published earlier this month by the World Resources Institute. The countrys leadership has said it will only make voluntary contributions, and that developed nations should still be the ones responsible for mandatory payments under the new finance goals.Talks at COP29 arent going very well. The COP29 president called for faster action, but progress toward a finance deal has stalled amid infighting over how much money should be on the table and who should pay up.Chinas complex role in emissions and climate action is far from the only holdup at the talks. Leaders from major nations including Germany and France canceled plans to attend, and the looming threat that the US could pull out of the Paris climate agreement is coloring the negotiations.But disagreement over how to think about Chinas role in all this is a good example of how difficult it is to assign responsibility when it comes to climate change, and how much is at play in global climate negotiations. One thing I do know for sure is that pointing fingers doesnt cut emissions.Now read the rest of The SparkRelated readingDig into the data with me in my latest story, which includes three visualizations to help capture the complexity of global emissions.Read more about why global climate finance is at the center of this years UN climate talks in last weeks edition of the newsletter.Keeping up with climateFusion energy has been a dream for decades, and a handful of startups say were closer than ever to making it a reality. This deep dive looks at a few of the companies looking to be the first to deploy fusion power. (New York Times) I recently visited one of the startups, Commonwealth Fusion Systems. (MIT Technology Review)President-elect Donald Trump has tapped Chris Wright to lead the Department of Energy. Wright is head of the fracking company Liberty Energy. (Washington Post)In the wake of Trumps election, it might be time for climate tech to get a rebrand. Companies and investors might increasingly avoid using the term, opting instead for phrases like energy independence or frontier tech, to name a few. (Heatmap)Rooftop solar has saved customers in California about $2.3 billion on utility bills this year, according to a new analysis. This result is counter to a report from a state agency, which found that rooftop panels impose over $8 billion in extra costs on consumers of the states three major utilities. (Canary Media)Low-carbon energy needs much less material than it used to. Rising efficiency in making technology like solar panels bodes well for hopes of cutting mining needs. (Sustainability by Numbers)New York governor Kathy Hochul has revived a plan to implement congestion pricing, which would charge drivers to enter the busiest parts of Manhattan. It would be the first such program in the US. (The City)Enhanced geothermal technology could be close to breaking through into commercial success. Companies that aim to harness Earths heat for power are making progress toward deploying facilities. (Nature) Fervo Energy found that its wells can be used like a giant underground battery. (MIT Technology Review)