"There is/are an increase in solar energy use and a decrease in coal consumption this year."
is
"There is an increase in solar energy use and a decrease in coal consumption this year."
"Every piece of litter counts/count towards the pollution of the park."
counts
"Every piece of litter counts towards the pollution of the park."
"Both the river and the lake is/are suffering from pollution."
are
"Both the river and the lake are suffering from pollution."
There is/are a need for immediate action to reduce pollution in our oceans.
is
There is a need for immediate action to reduce pollution in our oceans.
"All the plastic in our oceans are/is damaging marine ecosystems."
is
"All the plastic in our oceans is damaging marine ecosystems."
"The government has/have introduced new regulations to protect endangered species."
has
The government has introduced new regulations to protect endangered species."
"There is/are many factors contributing to climate change, including carbon emissions and deforestation."
are
"There are many factors contributing to climate change, including carbon emissions and deforestation."
Recycling reduce/reduces the amount of waste in landfills and saves natural resources.
reduces
Recycling reduces the amount of waste in landfills and saves natural resources.
"Renewable energy sources is/are replacing fossil fuels in many countries."
are
"Renewable energy sources are replacing fossil fuels in many countries."
"Some of the measures was/were ineffective in reducing pollution."
were
"Some of the measures were ineffective in reducing pollution."
"The committee meet/meets every Thursday to discuss environmental policies."
meets
"The committee meets every Thursday to discuss environmental policies."
The ban on single-use plastics has/have led to a decrease in ocean pollution.
has led
The ban on single-use plastics has led to a decrease in ocean pollution.