Technology may have unexpected, or unanticipated harmful side affects. Some of the following will fall under this category:
Cars emit smoke through their tail pipe which contains a gas called carbon dioxide. Excessive Carbon dioxide can cause "global warming" resulting in increased temparatures around the world include at the poles causing the ice caps at the poles to melt in summer.
we use fertilizers in our farms to produce more food. These fertilizers can drain into waterways and pollute waterways.
we use pesticides in our farms to kill harmful pests that would otherwise damage crops. The pesticides can get into the fruits and vegetables that we use. The pesticides can also run off into water streams.
Watching too much TV and not doing enough exercise can cause obesity in people.