Stories tagged New York Times

Sep
20
2011

There’s been some buzz about the relationship between clouds and climate recently, prompting Andrew Revkin of the New York Times’ Dot Earth blog to get his panties in a twist about the “…over-interpretation of a couple of [scientific] papers…”

What gives? I wanted to know too, so I’ve done a bit – ok, a lot – of research and this is what I can tell you: The heart of the discussion is not whether there is a cloud-climate connection (that’s clear), but rather over what that relationship behaves like. There are at least three possible theories, but before we get to those, let’s review some important background concepts.

Gimme the Basics First

Cloud Formation

First, scientists think of air as units of volume called air masses. Each air mass is identified by its temperature and moisture content. Clouds are basically wet air masses that form when rising air masses expand and cool, causing the moisture in the air to condense. You can see the process in action yourself just by exhaling outside on a cool morning. The Center for Multiscale Modeling of Atmospheric Processes has a webpage to answer your other questions about clouds.

Earth’s Energy Budget
Earth's energy budget: Incoming solar energy is either absorbed (orange) or reflected (yellow).  Outgoing energy is radiated (red).  The arrows show the direction and magnitude of movement where thick arrows signify bigger movements.
Earth's energy budget: Incoming solar energy is either absorbed (orange) or reflected (yellow). Outgoing energy is radiated (red). The arrows show the direction and magnitude of movement where thick arrows signify bigger movements.Courtesy NASA

Energy from the Sun is essential for life on Earth. Let’s pretend the Earth has an “energy budget” where solar energy is like money, absorption is like a deposit, reflection is like a transfer, and radiation is like a withdrawal. It’s not a perfect analogy, but it’ll work for starters: Most of the incoming solar energy (money) is absorbed by (deposited into) the ocean and earth surface, but some is absorbed or reflected (transferred) by the atmosphere and clouds. Most of the outgoing energy is radiated (withdrawn) to space from the atmosphere and clouds. The figure to the right illustrates this process.

The Greenhouse Effect

Thanks to the greenhouse effect, our planet is warm enough to live on. The greenhouse effect occurs within the earth’s energy budget when some of the heat radiating (withdrawing… remember our budget analogy from above?) from the ocean and earth surface is reflected (transferred) back to Earth by greenhouse gases in the atmosphere. Greenhouse gases include carbon dioxide, methane, and water vapor. This National Geographic interactive website entertains the concept.

Climate Change

Climate change is occurring largely because humans are adding more greenhouse gases to the atmosphere. More greenhouse gases in the atmosphere means more heat reflected back to earth and warmer temperatures. Warmer temperatures might sound pretty good to your right now (especially if you live in Minnesota and could see your breath this morning as you walked to school or work), but it’s not. Why? Check out NASA’s really great website on the effects of climate change.

Alright, already. What’s the climate-cloud relationship?

From what I can tell, there are three possible theories about the climate-cloud relationship:

  • Clouds actively drive climate change. This is a linear process where clouds reflect too much heat back to Earth, which increases the average global temperature and causes climate change.
  • Clouds passively blunt climate change. This is a cyclical process where more climate change includes increasing average global temperature, which increases average global evaporation, which creates more clouds. More clouds absorb more heat, keeping the average global temperature from rising even faster and lessening climate change. This slows down (note: it does not stop) the rate of climate change.
  • Clouds passively amplify climate change. This is a cyclical process where more climate change includes increasing the average global temperature, which increases average global evaporation, which creates more clouds. More clouds reflect more heat back to Earth, which raises the average global temperatures and worsens climate change. This speeds up the rate of climate change.
  • So which is it? Probably NOT Theory #1. Maybe Theory #2… or maybe it’s Theory #3? Scientists aren’t quite sure yet, so neither am I, but the evidence is stacking against Theory #1 leaving two possible options. The next big question seems to be surrounding the size of the effects of Theory #2 and Theory #3.

    Using what you just read about cloud formation, the earth’s energy budget, greenhouse gases, and climate change (Woah. You just learned a lot!), what do you think? What’s the climate-cloud relationship?

    If you want, you can read more about what scientists are saying about the climate-cloud relationship here:

Sep
23
2010

You might be aware of phosphorus, P, as a key ingredient in your lawn fertilizer. Or, perhaps you’ve seen “Does not contain phosphates” labels on your household detergents. If you haven’t seen these labels yet, chances are high you’ll see them soon. Why??

Phosphorus is Useful as Fertilizer and Detergent...

Fertilizer with P: See the N-P-K?  The P stands for phosphorus.  The number 21 below it tells us the percent of P in the fertilizer.  Many lawn fertilizers are now 0% P.
Fertilizer with P: See the N-P-K? The P stands for phosphorus. The number 21 below it tells us the percent of P in the fertilizer. Many lawn fertilizers are now 0% P.Courtesy Malawi MV project work

Phosphorus is a life-supporting mineral, which is why so many fertilizers contain it. Phosphates, the naturally occurring form of phosphorus, help soften water, form soap suds, and suspend particles making them choice detergents. Supporting life and keeping clean would normally be good things, but phosphorus has a dark side too.

... But, Phosphorus Causes Smelly, Dead Eutrophication

Because phosphorus is so good at growing stuff, it is actually harmful to the environment when it becomes dissolved and concentrated in bodies of water. Phosphorus-rich lakes cause algae blooms – huge increases of algae in a short period of time (kind of like the post-World War II Baby Boom, but for algae). Besides being smelly and turning water green, algae “breathe” the oxygen right out of the lake! Stealing dissolved oxygen even in death, algae create hypoxia – low oxygen, which prevents most other living things from surviving in the surrounding area. This whole process, from phosphorus-loading to algae bloom to hypoxia, is called eutrophication. There are other environmental and health risks to phosphorus, but eutrophication is what politicians are talking about around the water cooler these days.

Icky Algae Bloom: Algae blooms occur in nutrient-loaded water bodies and often led to hypoxia in a process called eutrophication.
Icky Algae Bloom: Algae blooms occur in nutrient-loaded water bodies and often led to hypoxia in a process called eutrophication.Courtesy Felix Andrews

Seventeen States Banned Phosphorus in Automatic Dishwashing Detergents

Deciding that euthrophication was yucky, in July, 17 states, including the entire Great Lakes Commission of which Minnesota is a member, passed laws banning phosphates from automatic dishwasher detergent. That might not seem like a big deal, but automatic dishwasher detergent is said to comprise between 7-12% of all the phosphorus making it into our sewage system (source). Previous legislation has limited or banned phosphorus in lawn fertilizers and laundry detergents.

Consumers Asked to Cope

According to a recent New York Times article, some consumers are getting their feathers ruffled as detergent manufacturers re-do their formulas to comply with state laws. The primary complaint is that the phosphate-free detergents don’t clean as well as traditional formulas. Consumer Reports concurred: of 24 low- or no-phosphate detergents tested, none matched the cleaning capabilities of detergents with phosphates. It may be uncomfortable at first, but learning to cope in a low-phosphorus world is already having environmental and human health benefits.

Green Cleaning: There are several line of green cleaning products that contain low- or no-phosphates.
Green Cleaning: There are several line of green cleaning products that contain low- or no-phosphates.Courtesy Becoming Green

Rest assured, industry officials still want your business and are continually improving their formulations. Indeed, the same Consumer Reports article mentioned above rated seven low- or no-phosphate detergents as “very good.” For the curious, there is a multitude of other websites reviewing phosphate-free detergents online. Pre-rinsing and/or post-rinsing have also been cited as ways to deal with phosphate-free dishwashing detergents.

Peak Phosphorus: Another Consideration

If you still aren’t convinced of the switch, consider this: we’re running out of phosphorus like we’re running out of oil. Phosphorus is a mineral, mined from naturally occurring phosphates, and we’re mining it faster than geologic cycles can replenish it. One Scientific American article cites the depletion of U.S. supplies in a few decades (world supplies may last for roughly another 100 years) given current consumption rates. Without phosphorus, world food production will plummet and with a global population soaring towards 9 billion people, that would be a very sorry state of affairs. If we succeed in limiting our phosphorus consumption, say, through eliminating it from household detergents, we may be able to continue using it in fertilizers and thus keep the human population fed well into the future.

What do you think? Is the phosphate-ban worth it?

Over at the New York Times, John Tierney has a science great blog, Tierney Labs : Putting Ideas in Science to the Test. One exemplary post highlights scientific research explaining why supermodels don't smile.