Pick out the activities that are not responsible for environmental problems.

Reforestation can help mitigate the impacts of deforestation and restore the benefits that forests provide. It is an important tool in the fight against climate change and in the conservation of the world's forests and the biodiversity they support.

Several human activities like agriculture, urbanization, industrialization, etc lead to environmental problems. 

Agriculture causes soil degradation and depletion of soil nutrients, water pollution due to the use of agricultural chemicals, and deforestation for crop and livestock farming.

Urbanization contributes to air pollution, water pollution, and waste generation. It also leads to the loss of wildlife habitat and increased energy consumption.

Industrialization leads to air and water pollution from factories, greenhouse gas emissions, and toxic waste disposal. It also leads to the depletion of natural resources and loss of wildlife habitat.

These activities can have negative impacts on both the environment and human health, and it's important to find ways to minimize their harm and promote sustainable practices.