Sens. Barbara Boxer (D-Calif.) and John Kerry (D-Mass.) plan to introduce their climate bill tomorrow. Here are a few brief notes on what to watch for.

Just as a reminder, for the non-wonks, here’s how the process works: 1) House passes bill, 2) Senate passes bill, 3) House and Senate bills reconciled via conference committee, 4) House and Senate both vote on resulting bill, and, finally, 5) president signs bill. Yes, it’s a torturous, somewhat ridiculous process, with dozens of points at which it can go off the rails.

The thing to remember is that #2 — which begins tomorrow — is a very different process than #1. In the House, just one committee was involved: Energy & Commerce. That committee has a fairly diverse membership, so Sens. Henry Waxman (D-Calif.) and Edward Markey (D-Mass.) had to contend with a broad array of interests, but ultimately Waxman’s hand was on the tiller through the whole journey. The committee produced a bill and it went to the floor for a vote.

It’s not so simple in the Senate. (Is anything simple in the Senate?) There, up to five committees may hold hearings and mark up legislation, which will ultimately have to be incorporated into one comprehensive bill by Majority Leader Harry Reid. Potentially weighing in: Environment & Public Works, Energy & Natural Resources, Finance, Agriculture, and Foreign Relations.

It’s possible Foreign Relations (which Kerry chairs) will bow out. Ag, now chaired by the climate-hostile Blanche Lincoln (D-Agribiz), will likely want to extract its chunk of flesh on carbon market regulation and agricultural offsets. Finance, chaired by the dread Max Baucus (D-Mont.), will want to have a hand in allowance allocation, though Boxer (or Reid) may yet convince him to back off. Energy, under Jeff Bingaman (D-N.M.), has already passed its bit, the American Clean Energy Leadership Act, a comparatively weak energy title relative to what’s in the House bill.

Boxer’s committee, EPW, is one of the Senate’s most progressive, and what Boxer and Kerry will introduce tomorrow is widely expected to mark the left edge of the debate — everything that follows will push the bill in a weaker direction. They’ve said that they’ll model their bill on the House-passed American Clean Energy & Security Act (ACES), which is somewhat unfortunate since ACES already represents the result of numerous compromises in the House. But such is the U.S. Senate.

Boxer and Kerry have signaled that they’ll make a few improvements on ACES. For one thing, they’re expected to bump the 2020 target from 17% (below 2005 levels) to 20%. They’re also expected to restore the EPA’s New Source Review authority over CO2, which could be quite contentious.

A few things worth keeping an eye on:

  1. Some members of Boxer’s committee, including Jeff Merkley (D-Ore.), have expressed concerns over regulation of carbon markets. ACES actually includes some fairly stringent provisions along these lines, but many enviros think they’re not enough to prevent speculation and market manipulation. (NRDC’s Andy Stevenson has a great post on the regulations in ACES and how the Senate could improve them.) It’s worth noting that it was ag interests that pushed for the Commodity Futures and Trading Commission (CFTC) to be involved in regulations, so it’ll be interesting to see if Boxer and Kerry include anything that will ruffle Big Ag’s feathers.
  2. Baucus has said he wants Finance to control the allocation of emission allowances, but it’s such a central part of the bill that Boxer and Kerry will almost certainly have something to say about it. It will be interesting to see how deep they get into this, as it could be the first shot fired in a power struggle between Boxer and Baucus. One of the central critiques of ACES is that it gives too many allowances away (though the reality is somewhat more complicated than that), putting the burden on the middle class. Naturally conservative Dems want even more credits given away. Will Boxer and Kerry try to push the free allowances down in anticipation of that fight?
  3. Kerry has said that they will try to boost the money devoted to adaptation assistance for developing countries. This is a crucial point of debate in international negotiations — while everyone agrees developed countries should help developing countries adapt to climate impacts, which will hit them first and hardest, the amount of that assistance is in hot dispute. Developing countries want way more than developed nations have yet put on the table. If the Senate can boost adaptation money — even as a symbolic gesture, since the bill is unlikely to pass before Copenhagen — it could send a welcome signal to the international community.

There’s likely more I’m forgetting, but that’s a start.