Human manipulation of Earth’s water systems is arguably the greatest accomplishment of our civilization. But our efforts to water crops, provide clean drinking water and remove waste from our living spaces may also be the worst thing we’ve done to the planet.
Earth’s Water Cycle
Hopefully by the time you’ve found this page, you’re pretty comfortable with the repeating process of
- Evaporation (water rising into air)
- Condensation (cloud formation)
- Precipitation (rain, snow, hail)
- Water flowing downhill and collecting in large sources to evaporate again.
How do we get water to our homes?
Requiring water for the function of our bodies and growth of crops meant the earliest people had to stay close to rivers and lakes. But as civilizations grew, the need for storing and transporting water over greater distances to more people changed the landscape.
How does our water use impact the planet?
How do agricultural chemicals impact water?
Agriculture chemicals “runoff” into water systems
Most farming chemicals are dissolved into water and sprayed onto croplands. These pesticides and fertilizers are meant to stay on the field and do their job, but rainfall will often re-dissolve excess chemicals on the surface and carry them off into the waterways where they don’t belong.
Excess Fertilizer causes algae blooms
In wild ecosystems, plants remove nutrients like Nitrogen, Potassium and Phosphorus to create their body structure and food and animals return them to the soil after eating in their waste. But since humans don’t return our waste to crop fields, chemical fertilizers are used to give the plants these nutrients. When fertilizers build up in lakes or shorelines, water plants called algae to grow out of control (aka Bloom), which then cause fish to die off.
Pesticides in runoff kill unintended targets
Pesticide is a broad term used to describe chemicals that kill things that bother crops
Pesticide is a broad term used to describe chemicals that kill things that bother crops. But unfortunately, things designed to kill one living thing typically cause harm to other species. Evidence is mounting that the majority of species (ourselves included) are experiencing negative health effects from these chemicals.
Check out the data on Fish Populations and Farming Chemicals
Fish of course! Our scaley friends are being assaulted on a number fronts. But let’s focus on chemicals from agriculture.
Figure 1: Freshwater Fish Abundance
Figure 2: Global Synthetic Fertilizer Use
Figure 3: Glyphosate (Roundup) Pesticide use by crop, year and US location.
What conclusion can be drawn from the Figures above?
Pesticides are harming humans too
While the original intention with pesticides was to provide more food to more people, we are realizing that they are harming us too! People who work at or live near farms obviously get higher doses. But all of us ingest small amounts that don’t wash off our food each day. And water treatment facilities aren’t capable of removing all of the fertilizer and pesticides that make their way to our drinking water in rivers and streams. So this buildup of tiny amounts of these chemicals is creating lots of health problems as seen here:
So how are we supposed to feed 8 Billion people without chemical fertilizers and pesticides that are ruining our water ecosystems?
