Archive for Nursery

Water: The Measure of America

A subtle death-process played a godfather role in the conception and designing of the refrigerator, the vacuum cleaner, the automobile, and the turbine. Natural laws were stripped of wisdom and projected into matter. — Theodor Schwenk.

Thelma and Harold Grochocki (the couple in the cartoon, in case you didn’t recognize them) not only sprayed a heavy dose of some pretty deadly roachicides yesterday; they also fertilized, mowed, and watered their lawn, ate their fill of burgers, steak, bacon. and eggs, drove their van 63 miles, poured half a can of paint thinner and a jar of pickle juice down the drain, watched TV most of the afternoon, washed their clothes, their dishes, and their dog, bathed, perfumed, and deodorized their bodies, vacuumed the carpet, and urinated and defecated repeatedly. It is interesting that although they spent most of their day at activities that directly or indirectly contaminate water, they seem surprised that the stuff that flows on demand from the kitchen tap isn’t pristine mountain spring water. Read more

Water Funds: Investing in Nature and Clean Water

Our water comes from nature. The vast majority of the world’s population depends on rivers and lakes to supply water for drinking, cooking, growing crops and more (i). Yet worldwide we are crippling nature’s ability to provide the clean water we need in order to live and to thrive.

Scientists predict that, if we continue on our current course, two-thirds of the world’s population will face water shortages by 2025.

As the world’s forests and grasslands are degraded or removed, the threats to our water supplies grow. The roots of trees and other native vegetation filter water, prevent erosion and slow water down, helping keep flow levels steady. Without this protective system, lakes and rivers are exposed to soil run-off, chemicals and other debris carried across the land by rain and snowmelt.

When sediment and pollution wash into our waterways, businesses, communities and governments are forced to pay higher costs for water treatment. In vulnerable communities that simply cannot afford water treatment, people face increasingly dirty, unhealthy water. Read more

What makes sea-level rise?

Last week the science community was shocked by the claim that 42% of the sea-level rise of the past decades is due to groundwater pumping for irrigation purposes. What could this mean for the future – and is it true?

The causes of global sea level rise can be roughly split into three categories: (1) thermal expansion of sea water as it warms up, (2) melting of land ice and (3) changes in the amount of water stored on land. There are independent estimates for these contributions, and obviously an important question is whether their sum is consistent with the total sea level rise actually observed.

 foto (c) Stefan Rahmstorf 2012

In the last IPCC report (2007), the time period 1961-2003 was analysed in some detail, and a problem was found: the individual contributions summed up to less than the observed rise – albeit with rather large uncertainties in the estimates. In the years since then, much research effort has been devoted to better quantify all contributions. For the last decade there is also improved observation systems, e.g. the GRACE satellite mission and thousands of autonomous ARGO floats monitoring globally the warming ocean. Read more

10 Most Incredible Waterfalls of Ice

 

We’re used to seeing stunning images of cascading waterfalls in all their fluid glory, but have you ever wondered how they would look if Jack Frost was let loose on them? Well, you need wait no longer as we have compiled a range of fantastic frozen waterfalls.

1. This enchanting image of an ice waterfall perfectly captures the force and flow of the water underneath the ice, making it hard to comprehend how it ever manages to freeze. Read more

Capillary action

Even if you’ve never heard of capillary action, it is still important in your life. Capillary action is important for moving water (and all of the things that are dissolved in it) around. It is defined as the movement of water within the spaces of a porous material due to the forces of adhesion, cohesion, and surface tension.

 

 

Capillary action occurs because water is sticky, thanks to the forces of cohesion (water molecules like to stay close together) and adhesion (water molecules are attracted and stick to other substances). Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact. Capillary action occurs when the adhesion to the walls is stronger than the cohesive forces between the liquid molecules. The height to which capillary action will take water in a uniform circular tube (picture to left) is limited by surface tension and, of course, gravity. Read more