Too Many To Mention but some are

Deforestation - destruction of big areas of forests
              Effects: landslides, greenhouse effect, flooding, etc.

Flash Flood - sudden flood of great volume, usually caused by heavy rain
               Effects:loss of life, contamination of drinking water, causes of water                                          borne diseases, etc.

Soil Erosion - happens when soil and rocks are moved from one place to another by wind, water, and gravity.
                 Effects: unproductive use of farmland, loss of soil for vegetation which                            causes climate change, difficulty in raising of livestock

Coral Reef Degradation - significant problem throughout the world. It has been acknowledged that 27% of he world's reef have been affected
                  Effects: loss of edible reef fish, reduction of species diversity and                            richness, and alteration in he size structure of target species

And the major problem of the earth is POLLUTION. Any alteration of the chemical, [physical and biological properties of water, air and/or land resources is POLLUTION.

hope it helped :))