Walmart’s green PR machine has been running on overdrive lately. Over the past few weeks, the world’s largest retailer has announced six new solar installations in Colorado, unveiled its fifth annual Global Responsibility Report, and promoted a live webcast of its Global Sustainability Milestone Meeting. Walmart Chair Rob Walton donated $27.5 million to Arizona State University’s Global Institute of Sustainability, and both he and the company’s top marketing guy, Duncan Mac Naughton, spoke at the Fortune Brainstorm Green conference.

Why the gush of the green hype? Maybe to distract us from not-so-flattering news, like a recent Consumer Reports survey that ranked Walmart as the second-to-worst supermarket chain in the U.S.? Or to keep us from noticing the company’s evasions about whether it sells genetically engineered sweet corn or ground beef made with pink slime?

There are lots of hard questions to be asked about Walmart’s commitment to sustainability — and very few of them are answered in the company’s new Global Responsibility Report.

This year’s glossy, photo-rich report goes on for 126 pages about how great Walmart is to its employees, suppliers, the environment, and the communities in which it operates. The section on sustainability seems thorough at first glance — there are certainly lots of statistics and small details on this or that program. But if you try to really digest the content and compare it to reports from previous years, you begin to realize that much of the data is elusive. The same stats aren’t reported consistently each year. The metrics shift; promises touted one year are glossed over the next.

More significant are the many fundamental problems with Walmart’s business model that these reports do not address, or even mention. It’s as though, by loading up on pretty pictures and keeping the figures and details narrow, Walmart hopes readers will miss the forest for the trees.

To help people better evaluate Walmart’s claims of being a green leader, Food & Water Watch and the Institute for Local Self-Reliance have published the Top Ten Ways Walmart Fails on Sustainability. Here’s a quick rundown:

1. Selling Shoddy Products. Walmart drives down the quality and durability of consumer goods, expanding the amount of stuff Americans buy and discard. (See: Is your stuff falling apart? Thank Walmart)

2. Reducing Waste According to Whom? The gains made by the company’s much-publicized store-waste reduction program are miniscule compared to the volume of pollution and trash that result from consumption of Walmart goods.

3. Lagging on Renewable Energy. At its current pace, it will take Walmart many decades to reach its stated goal of running on 100 percent renewable power. Though its operating profits last year were $26.6 billion, Walmart excuses its slow progress on renewables by saying the technologies are too costly. (See: Think Walmart uses 100% clean energy? Try 2%)

4. Increasing Greenhouse Gases. Between 2005 and 2010, Walmart’s reported emissions grew by 14 percent, and it expects its emissions to continue expanding despite promises to improve energy efficiency and cut emissions at its 2005 base of stores and distribution centers by 20 percent by the end of 2012.

5. Voraciously Consuming Land. Since 2005, Walmart has added more than 1,100 supercenters in the U.S., expanding its store footprint by one-third.Most of these stores were built on land that hadn’t been developed before, including, in some cases, critical habitat for threatened and endangered species. (See: Can you say ‘sprawl’? Walmart’s biggest climate impact goes ignored)

6. Financing Anti-Environment Candidates. Since 2005, nearly 60 percent of the $3.9 million Walmart has given to members of Congress went to lawmakers who vote against the environment on most critical measures, according to the League of Conservation Voters. (See: Walmart spends big to help anti-environment candidates)

7. Consolidating and Industrializing Food Production. Although Walmart claims to support “sustainable agriculture,” it has used its market power to usher in a larger-scale, more industrialized food system. Walmart controls more than 50 percent of total grocery sales in 29 metro markets, and the company’s buying power and business practices have triggered a wave of mergers among meatpackers, dairies, and other food processors. (See: Eaters, beware: Walmart is taking over our food system)

8. Redefining Local. Walmart claims to be increasing the amount of locally produced food it sells, but the company’s distribution model favors the use of very few large suppliers, not the small farms most consumers think of when they seek out local produce.

9. Degrading Organic. When Walmart talks about organic, it generally means big-brand organic versions of the processed foods that are already on its shelves, like Rice Krispies and Kraft macaroni and cheese. Walmart’s private-label organic milk has been criticized for coming from cows raised in factory-farm conditions.

10. Spreading Poverty. When Walmart comes into a community, incomes decline and poverty increases. According to a study published in Social Science Quarterly, neighborhoods that gain Walmart stores end up with more poverty and food-stamp usage than communities where the retailer does not open.

If Walmart really wanted to walk its green talk, it could begin by addressing these fundamental problems. In the meantime, we all need to keep Walmart in the hot seat.

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