The National Labor Board has determined that Amazon illegally retaliated against two workers, Emily Cunningham and Maren Costa, last year. Cunningham and Costa had publicly pushed the company to reduce its impact on climate change and address concerns about its warehouse workers. The two women were among dozens of Amazon workers who in the last year told the labor board about company retaliations, but in most other cases the workers had complained about pandemic safety. This week, the national labor board is counting thousands of ballots that will determine whether almost 6,000 workers will form a union at an Amazon warehouse outside Birmingham, Ala., in the largest and most viable labor threat in the company’s history. The union has said the workers face excessive pressure to produce and are intensely monitored by the company to make sure quotas are met.