Oh, global warming. They have projections of what their industries will do to the global climate over time but no real traction on how to stop it, and yes, it hasn't been on their priority list, but it would be appreciated for the after. There's a chance a tinker might come up with something, but it wouldn't be scalable. Climate engineering might be necessary anyway to repair the environmental damage a fight with Scion could cause.
As to what she needs to stop him...
She doesn't know.
It's probably not going to be in the form of—shooting lasers and beating him up—his true body probably can't be damaged by hurting his avatar, and there's a good chance he'd win instantly if given the right motivation, so they don't want a drawn-out fight. There are capes who can mind control or instantly kill people at a distance, and since those powers came from Scion, there's no reason to think he can't do the same, potentially on massive scales. He's a higher-dimensional being spread across and between worlds, so they don't have the leverage to interact with most of him except some guesses that might not work.
There is some way to defeat or drive him off, even with only the resources her home universe. Precogs project a low but existent chance of humanity surviving through it. They may be overestimating how much power Scion has left. Still, because Scion disrupts many forms of precognition, they haven't been able to determine how they win in the futures where they win.
With that in mind, the solution she's looking for is either a massively powerful interdimensional weapon—that's why she was asking Daisy about dimensional technology earlier—to snipe his critical mass across worlds before he can react, or a mental power of sufficient scope that it can command him into stopping. Or she can simply become so personally powerful across all axes she can find that she can wrestle Scion into submission on his own level while protecting the Earth from the collateral damage.