On a sultry June day, climate scientist James Hansen testified in front of a committee of the U.S. Senate, telling those assembled that “the greenhouse effect has been detected, and it is changing our climate now.“ That was in 1988.

Now, more than three decades later, Congress is poised to pass the first major climate legislation in U.S. history as part of the Inflation Reduction Act (IRA) of 2022. The bill, which has passed in the Senate, directs billions of dollars into clean-energy technology in an attempt to push the country toward President Joe Biden’s ambitious goal of reducing greenhouse gas emissions by about 50 percent by 2030. (Experts estimate the IRA will reduce emissions by about 30 to 40 percent.) Meeting that goal is necessary to help the world avoid the worst consequences of global warming by keeping the rise in global temperatures to less than two degrees Celsius—and ideally less than 1.5 degrees C—above preindustrial temperatures. The global average temperature has already risen by about one degree C above that baseline, so time is of the essence in tackling the climate emergency.

The IRA has engendered both surprised joy for the progress it represents and dismay over provisions it left out and the support it provides for the fossil fuel industry. On the eve of the bill’s possible passage by the House of Representatives, Scientific American reached out to climate scientists and policy experts to get their reactions to the momentousness of the legislation, as well as their insights about what needs to be done to continue the progress it has kick-started. Below are their answers, lightly edited for style and grammar.

Kim Cobb, a climate scientist and director of the Institute at Brown for Environment and Society

I have to admit that this bill’s passage comes as a welcome shock. The fact that something this impactful can move forward in this political environment makes it clear that climate is finally a priority to enough lawmakers in Washington, D.C. It’s exciting to imagine what’s possible in the realm of climate resilience and adaptation, which demands an equally large, if not larger, investment in the near term to deliver long-term benefits that dwarf that investment.

Everyone needs to realize that this must only be the beginning of a series of climate packages designed to make up for decades of climate inaction. The road ahead is still quite daunting, in terms of meeting emissions targets designed to keep climate damages to a bare minimum. But if we’ve done it before, we can do it again and again and again until we get the job done.

To my mind, continued momentum will require a continued focus on the needs of frontline environmental justice communities to have their experiences and their futures centered in our nation’s approach to climate action.

It also means making sure that every American can make a direct link between climate action and the safety and well-being of their families and their communities, today and going forward. That means accelerating adaptation and resilience efforts that can deliver concrete, near-term benefits to communities already reeling from climate change impacts.

Marshall Shepherd, director of the Atmospheric Sciences Program at the University of Georgia

This bill is a first step toward shattering climate “delayism.” I think most reasonable people understand that climate change is a threat to humanity now, but we have been stuck in delayism debates about what to do or how to pay for it. This finally gets us over the “spinning our wheels” stage. We know what to do—now let’s do it.

Leah Stokes, a climate policy expert at the University of California, Santa Barbara

We’ve never managed to pass comprehensive climate legislation through the American Congress—people have been trying to do it for decades, but it has proved near-impossible. And meanwhile the planet has continued to warm, and communities have continued to be poisoned by the fossil fuel industry. So getting a bill across this finish line will be huge. It’ll be completely historic.

But this is a down payment; it is not full climate victory. No one bill was ever going to do it all. This will get us on a pathway to cutting carbon pollution by 40 percent below 2005 levels by 2030. That’s really important, but we need to go even further. There were certain things that were left out of the bill, such as the Civilian Climate Corps, which was an important priority of the Sunrise Movement to help young people feel like they had jobs and a place in cleaning up all the harms of the fossil fuel industry. And there were also provisions put in this bill, for example, requiring oil and gas lease options that are terrible, and it would be good to be able to go back and clean those up in the future. So we need more money; we need more programs to fix some of the problems that this bill is creating.

Robert Bullard, an environmental policy and justice expert and director of the Bullard Center for Environmental & Climate Justice at Texas Southern University

The IRA has some good things in it that are greatly needed by low-income people, people of color and environmental justice communities—such as incentives for clean-energy technologies, electric vehicles, school buses and transit; helping families who are energy insecure with their electric bills; retrofits and tax credits to assist with making homes more energy efficient; targeted investments to address legacy pollution and environmental “hotspots” created by racial redlining and environmental racism that have contributed to elevated health disparities and climate threats; and resources to address bad transportation infrastructure and highway projects that have caused displacement, disinvestment, economic isolation and theft of transformative wealth from Black and other people of color who are homeowners and business owners.

The more than 725-page Senate bill has nearly $370-billion investments to address greenhouse gas emissions and about $60 billion to advance environmental justice and health equity. Given the urgency of the climate crisis and the disparate impact on disadvantaged communities, the amount set aside for environmental justice is inadequate. At minimum, Congress should use the “Justice40” framework [the goal for 40 percent of the benefits of certain federal investments to go to underserved communities overburdened by pollution] in allocating the bill’s $370-billion climate funding—investments and benefits that are desperately needed and long overdue.

There are provisions and incentives in the bill that run counter to reducing greenhouse gas emissions and relieving legacy pollution, health threats, and the pain and suffering of already overburdened environmental justice communities. This is especially the case in the Gulf Coast region: I have written about and documented over the decades how the oil and gas and petrochemical industry created environmental “sacrifice zones” and “Cancer Alley” there. Once again, the current Senate bill includes gifts—tax credits to these same fossil fuel companies for the unproved carbon capture and storage (CCS), more offshore oil and gas leases, and more pipeline guarantees for new fossil fuel leasing in the Gulf of Mexico.

These contradictions should not be brushed aside or ignored. The funding contradictions need to be rigorously assessed and improvements need to be made in the bill to minimize negative impacts that fall disproportionately on our most vulnerable population and communities wherever they are found.

Robert Rohde, lead scientist at the climate nonprofit Berkeley Earth

The IRA is, by far, the largest climate bill in U.S. history. I believe that this is a turning point that will put the U.S. firmly on the path toward reducing carbon emissions through the deployment of alternative energy systems. But while the IRA is projected to put the U.S. on a pathway toward clean energy, it still falls a bit short of the reductions that would be needed to meet the stated ambition of limiting global warming to 1.5 degrees C. Hopefully, the investments that the IRA makes will help to unlock further improvements by driving down costs and signaling the U.S.’s commitment to a clean-energy transition. State and local governments can also drive further reforms through their own initiatives. More needs to be done, both to meet previously stated 2030 goals and to ensure that we are prepared to continue emissions reductions well beyond 2030.

In addition, it is important to remember that the U.S. cannot solve climate change by itself. We need international cooperation to combat climate change. Much of that work has already begun through the Paris Agreement, but bringing affordable clean energy to the whole world remains a massive undertaking. We will still need governments, entrepreneurs, financiers, engineers, activists and many others coming together to make the clean-energy transition efficient and affordable for everyone.

Andrea Dutton, a climate scientist at the University of Wisconsin–Madison

If the IRA passes in the House, it will mark a historic turning point for the U.S. as the first major piece of legislation to limit our carbon emissions and hence future warming of our planet. The outline of where we go from here is already written in the shortcomings of this bill: we must stop investing in fossil fuel infrastructure and make this legislation merely a first step of many more meaningful steps to come. Most importantly, every single future step needs to center on environmental justice. The takeaway is that we need to build on this momentum because time matters—the faster we slash our carbon emissions, the better the outcome for everyone on this planet.

Bob Kopp, a climate scientist at Rutgers University

The IRA, which achieves emissions reductions largely through tax credits, creates an enabling environment for hitting the 2030 target. Climate action across the country—at state and local levels, in businesses and other organizations, and in our households—is necessary both to realize the mitigation reductions enabled by the act and to close the remaining gap. For example, the act makes it much more cost-effective to electrify water and air heating in houses, but households still need to be informed and organized enough to make the switch from fossil fuels.

In addition, the bill is focused heavily on the problem of limiting greenhouse gas emissions—there is still a lot more that needs to happen, including, at a federal level, to prepare the country to manage the consequences of climate change.