Wind energy is generally considered an environmentally friendly source of energy because it does significantly smaller damage to our environment when compared with currently dominant fossil fuels.
The environmental issues connected with wind turbines mostly refer to excessive noise and bird killings.
The current trend in wind energy industry is to build large wind turbines with huge blades and these turbines produce high levels of noise when operating. The technology is constantly moving forward but wind energy industry is still having major difficulties to reduce the levels of noise connected with wind turbines.
Wind turbines can also hurt wildlife, particularly birds. There have been various reports where birds have been found dead around the base of turbines as they have been caught by fast-rotating large blades. Birds are not the only animals that can be negatively affected by wind turbines. Big wind turbines, for instance, require very deep foundations and this can negatively affect ecosystems in underground habitats.
These two environmental disadvantages shouldn't be ignored but they are still far from being regarded as the sufficient reasons to halt future wind energy development. Just look at the levels of environmental damage that are done by our dependence on fossil fuels (climate change and pollution) and wind energy will certainly look like a more than acceptable alternative.
Wind energy is not perfect source of energy but it sure beats fossil fuels when discussing the environmental impact. This however, does not mean that science shouldn't be searching for solutions to make wind turbines more environmentally friendly