The Central Commission for Discipline Inspection of the Communist Party of China has announced the investigation of the first "green tiger". The former vice-minister of environmental protection Zhang Lijun is the "tiger", or senior corrupt official, under investigation. He is the first senior official in the environmental protection system to be investigated for serious violations of the law and Party discipline after the 18th CPC National Congress.

Zhang's fall has drawn widespread public attention, as it indicates high-level corruption among those responsible for protecting the environment, which has become a major public concern due to serious widespread pollution and environmental degradation. Zhang is being investigated more than two years after he retired, which shows that retirement is not a steel safe for corrupt officials, and there is no "blind spot" in the anti-corruption campaign.

Environmental protection is a "high risk zone" of corruption. Last year, the minister of environmental protection revealed that from January 2012 to June 2013, altogether 977 people in the environmental protection system were investigated and punished according the Party's discipline and national law.

To protect the environment and fight against polluters, the authorities should first resolutely crack down on corruption activities in the environmental protection system.