Four large smokestacks at a power plant.

New Power Plants

  • 2007

    The U.S. Supreme Court con­firmed, in Mass­a­chu­setts v. EPA, 549 U.S. 497 (2007), that the Clean Air Act applies to green­house gas­es con­tribut­ing to cli­mate change. The courts have sub­se­quent­ly held that the Envi­ron­men­tal Pro­tec­tion Agency (EPA) must reg­u­late green­house gas­es fol­low­ing the release of its 2009 Endan­ger­ment Find­ing, in which the Agency deter­mined that car­bon diox­ide and oth­er green­house gas­es pose a threat to pub­lic health and the environment.

  • Octo­ber 2015

    On the same day that EPA final­ized the Clean Pow­er Plan in Octo­ber 2015 to restrict car­bon emis­sions from exist­ing fos­sil-fuel fired pow­er plants, the agency released a com­pan­ion rule to restrict car­bon emis­sions from new and mod­i­fied nat­ur­al gas and coal plants. The New Source Per­for­mance Stan­dards (NSPS) allows states to devel­op their own require­ments for ensur­ing that indi­vid­ual new facil­i­ties do not exceed numer­i­cal lim­its on the amount of car­bon each facil­i­ty emits per megawatt hour of electricity.


  • Octo­ber 2015

    The NSPS was imme­di­ate­ly chal­lenged in the D.C. Cir­cuit Court of Appeals by states and indus­try groups opposed to reg­u­lat­ing car­bon emis­sions from new pow­er plants. 

  • Novem­ber 2015

    In Novem­ber 2015, a coali­tion of 17 attor­neys gen­er­al led by the Cal­i­for­nia attor­ney gen­er­al suc­cess­ful­ly filed a motion to inter­vene in the lit­i­ga­tion in sup­port of the NSPS.

  • Novem­ber — Decem­ber 2015

    The Min­neso­ta attor­ney gen­er­al inter­vened lat­er in Novem­ber 2015 and Vir­ginia Attor­ney Gen­er­al Mark Her­ring suc­cess­ful­ly inter­vened in the lit­i­ga­tion in Decem­ber 2015; both inter­vened in sup­port of the NSPS.


  • Feb­ru­ary 2017

    In Feb­ru­ary 2017, the coali­tion of 19 attor­neys gen­er­al led by the New York and Cal­i­for­nia attor­neys gen­er­al filed their mer­its brief in sup­port of the NSPS. The attor­neys gen­er­al not­ed that the rule ful­filled EPA’s legal oblig­a­tion to reg­u­late car­bon emis­sions from new pow­er plants after its 2009 Endan­ger­ment Find­ing. Fur­ther, the rule sat­is­fied the Clean Air Act’s require­ment that the rule’s numer­i­cal lim­its on car­bon emis­sions reflect an ade­quate­ly demon­strat­ed best sys­tem of emis­sion reduc­tion (BSER) for car­bon pol­lu­tion from new nat­ur­al gas and coal plants.

  • March 2017

    In March 2017, with oral argu­ment sched­uled for the fol­low­ing month, EPA filed a motion to hold the case in abeyance as the incom­ing Trump admin­is­tra­tion reviewed the 2015 NSPS and con­sid­ered ini­ti­at­ing a rule­mak­ing process to pro­mul­gate a replace­ment new source standard.

  • March 2017

    At the end of March 2017, the D.C. Cir­cuit, upon con­sid­er­ing the abeyance motion, removed the lit­i­ga­tion from the April 2017 oral argu­ment calendar.

  • April 2017

    The coali­tion of attor­neys gen­er­al opposed EPA’s abeyance motion in April 2017, not­ing that the claims of oppo­nents of the rule were nei­ther moot nor unripe as, even if EPA did even­tu­al­ly replace the 2015 NSPS, at least some of the ful­ly briefed issues in the case would return to the D.C. Cir­cuit. Then, new North Car­oli­na Attor­ney Gen­er­al Josh Stein with­drew his state from the lit­i­ga­tion; the state had been chal­leng­ing the 2015 NSPS.

  • April 2017

    In April 2017, the D.C. Cir­cuit placed the case in abeyance and required EPA to file sta­tus reports on its process for review­ing the 2015 NSPS at 30 day inter­vals. In August 2017, the court ordered the case remain held in abeyance pend­ing fur­ther order of the court and instruct­ed EPA to file sta­tus updates every 90 days.

  • Jan­u­ary 2019

    In Jan­u­ary 2019, new­ly sworn-in Michi­gan Attor­ney Gen­er­al Dana Nes­sel with­drew her state from the lit­i­ga­tion in which it was sup­port­ing the chal­lenge to the 2015 NSPS. The lit­i­ga­tion over the 2015 NSPS remains in abeyance.



  • Decem­ber 2018

    In Decem­ber 2018, EPA released a pro­posed rule to weak­en the 2015 NSPS reg­u­lat­ing car­bon emis­sions from new and mod­i­fied pow­er plants. The pro­pos­al would adopt a new BSER that would allow for a sig­nif­i­cant increase in car­bon emis­sions from new coal plants. A new coal pow­er plant could release up to 35 per­cent more car­bon emis­sions under the pro­posed rule than a new coal plant can under the 2015 NSPS.

  • March 2019

    In March 2019, a coali­tion of 21 attor­neys gen­er­al, led by Cal­i­for­nia Attor­ney Gen­er­al Xavier Becer­ra, filed com­ments in oppo­si­tion to the pro­pos­al. The attor­neys gen­er­al not­ed that the pro­posed rule is arbi­trary and capri­cious in find­ing that the tech­nol­o­gy EPA adopt­ed as the BSER in the 2015 NSPS – car­bon cap­ture and stor­age (CCS) – is no longer the BSER. The agency’s BSER analy­sis manip­u­lat­ed cost data to sug­gest that the cost of employ­ing CCS is unrea­son­able and failed to estab­lish that CCS is insuf­fi­cient­ly avail­able and acces­si­ble through­out the coun­try to be the BSER.

    The com­ments also point­ed out that the pro­posed rule vio­lates the Clean Air Act. The pro­pos­al con­tra­venes the Clean Air Act’s man­date that the agency adopt a rule that reflects the best” sys­tem for reduc­ing emis­sions, as the proposal’s emis­sions stan­dard would allow emis­sions to increase.

  • Jan­u­ary 2021

    In Jan­u­ary 2021, the EPA pur­port­ed to release the final ver­sion of the NSPS for car­bon emis­sions from new and mod­i­fied pow­er plants. The action leaves the issue of BSER for NSPS for car­bon emis­sions for a lat­er action from the agency. Instead, rely­ing on a foot­note in the pro­posed rule, in which the agency solicit­ed com­ments on its inter­pre­ta­tion of endan­ger­ment find­ing,” it issued a sig­nif­i­cant con­tri­bu­tion find­ing” for source cat­e­gories under the Clean Air Act.

    The EPA adopt­ed a sig­nif­i­cant con­tri­bu­tion find­ing” of three per­cent of total U.S. green­house gas emis­sions for sources. Under the Clean Air Act, the EPA will be required to reg­u­late source cat­e­gories — includ­ing pow­er plants — that exceed the sig­nif­i­cant con­tri­bu­tion find­ing” thresh­old as EPA has deter­mined that the source cat­e­go­ry con­tributes sig­nif­i­cant­ly to air pol­lu­tion for which the EPA has issued an endan­ger­ment find­ing,” a deter­mi­na­tion that the pol­lu­ant will endan­ger pub­lic health or welfare.

    EPA’s sig­nif­i­cant con­tri­bu­tion find­ing” thresh­old, how­ev­er, means that the agency has deter­mined that source cat­e­gories, such as the oil and gas sec­tor, that emit less than three per­cent of total U.S. green­house gas emis­sions do not con­tribute sig­nif­i­cant­ly to the endan­ger­ment of pub­lic health or wel­fare due to cli­mate change. Con­se­quent­ly, under the final rule, the agency will have no respon­si­bil­i­ty to reg­u­late oth­er source cat­e­gories, such as the oil and gas sec­tor, that emit green­house gas emissions.

    EPA’s devel­op­ment of this final rule is like­ly unlaw­ful. Solic­it­ing com­ments in a foot­note of the pro­posed rule does not rep­re­sent a mean­ing­ful oppor­tu­ni­ty to com­ment on a pro­pos­al as required under the Admin­is­tra­tive Pro­ce­dure Act (APA) and the final rule is also not a log­i­cal out­growth of the pro­pos­al, like­ly anoth­er vio­la­tion of the APA.

  • Jan­u­ary 2021

    In Jan­u­ary 2021, Cal­i­for­nia Attor­ney Gen­er­al Becer­ra led a coali­tion of 21 attor­neys gen­er­al in fil­ing a peti­tion for review chal­leng­ing the law­ful­ness of the EPA’s Jan­u­ary 2021 rule. In April 2021, the D.C. Cir­cuit vacat­ed the rule.