Is the human species becoming a cancer on the planet? This question arises from the grim findings of a new United Nations study that human actions are irremediably altering natural ecosystems and driving increasing numbers of plant and animal species to extinction. "Nature across the globe has now been significantly altered," with 75 percent of the land surface extensively modified, 85 percent of the wetlands lost, and two-thirds of the oceans bearing mounting cumulative impacts, according to the study's just-released summary of findings. Another study published in this month's Nature, the journal of science, reports that humans have modified the flows of most long rivers other than those found in remote regions.

Not surprisingly, biodiversity is declining rapidly across the world. Aquatic ecosystems, for example, have lost 50 percent of their biodiversity since the 1970s. One major driver is plastic pollution.

Bottled water has become an important source of plastic waste, along with single-use straws, cutlery, food containers and other plastic items. Plastic debris is clogging up landfills, blocking drains, polluting waterways and contributing to biodiversity loss. Plastic litter on roadsides and beaches and in other public spaces is an eyesore.