Yesterday was Earth Day.

The annual celebration of the environment was first held in 1970.

But it wasn’t until 1990 that 141 countries put on special events at the same time to make people aware of environmental issues.

Now Earth Day is celebrated every April 22 in more than 150 countries.

In Canada, because there are so many events happening to commemorate Earth Day, the country now celebrates Earth Week and even Earth Month in some places.