From birth to puberty a hamster doubles its weight each week. If, then, instead of levelling-off in maturity as animals do, the hamster continued to double its weight each week, on its first birthday we would be facing a nine billion tonne hamster. If it kept eating at the same ratio of food to body weight, by then its daily intake would be greater than the total, annual amount of maize produced worldwide. There is a reason that in nature things do not grow indefinitely.

Growth isn’t possible argues that indefinite global economic growth is unsustainable. Economic growth is constrained by the finite nature of our planet’s natural resources.

Whether or not the stumbling international negotiations on climate change improve,  Growth isn’t possible makes clear that much more will be needed than simply more ambitious reductions in greenhouse gas emissions. Watch the hamster and then read the report. You’ll conclude that a new macro economic model is needed, one that allows the human population as a whole to thrive without having to relying on ultimately impossible, endless increases in consumption.

The retail sector will be paying close attention to shoppers in Barnsley over the next few weeks to monitor their response to Asda’s latest green initiative.

Asda is selling own-label fabric conditioner in re-useable pouches from vending machines. Part funded by WRAP, the trial starts at the Barnsley anchor store before being rolled out across another four.

The fabric conditioner is being be piped from 1,000 litre, re-useable containers from the back-of-store via overhead pipes to a dispensing point in the retail aisle. Shoppers can bring the pouch back for refilling at no extra cost to purchasing a standard bottle, in order to reduce the amount of packaging thrown away. And the maths adds up too. It allows customers to purchase concentrated fabric conditioner re-useable pouches that can be refilled up to 10 times, saving 40p each time compared to the same volume of product in traditional plastic bottles.

Apart from saving shoppers a few quid the move will cut the carbon impact across the supply chain. Of course, if the initiative does does take off, then perhaps the good folk of the Yorkshire town will be more like those often reviled southerners: a bunch of softies.

I know that I banged on about Wal-Mart and its Sustainable Product Index only a few days ago… forgive me because this short film is really worth watching. It’s an interview by Louella Miles with John Grant, which forms part of Louella and Laura Mazur’s ‘Conversations with Green Gurus’. Louella and Laura are two seasoned journalists, who always deliver the goods whether the topic is marketing, innovation or sustainability. The interview touches briefly on the retail giant, but is noteworthy for the engaging way they get John to talk about the business challenges of going green.

According to stats published by Cleantech Investor magazine the performance of cleantech stocks in the final quarter of 2009 bodes well for the sector this year.

First, the cleantech indices that the magazine had been tracking nearly all achieved healthy gains.

Second, the pace of cleantech initial public offerings on stock markets gathered significant momentum in the latter half of the year. There was the C$100 million IPO of geothermal energy business Magma Energy Corporation on the Toronto Stock Exchange in August 2009.

In the same month, wind farm developer Indian Energy completed a successful completion of its IPO raising £9.75m in a placing with existing stakeholders and new investors to give the firm a market capitalisation on listing of £20.3m.

Then, US battery business A123Systems raised more than $400 million as it joined NASDAQ. A123Systems, which owns lithium-ion battery technology, received a very strong reception to its IPO with its shares closing almost 20% higher than their opening price on the first day of trading. Just last week A123 announced a battery supply agreement with Fisker Automotive, a new American automaker building premium green vehicles. The supply agreement is for battery systems for the Fisker Karma. The Karma plug-in vehicle is scheduled to be launched in late 2010 and expected to be one of the cleanest, most fuel-efficient cars in the world while still offering industry-leading style and performance.

None of this is to say that the cleantech sector is a dead cert for investors. It has benefitted from investors in poorer performing asset classes switching stocks to achieve better returns. But cleantech investors should be looking beyond the short term to the future.

We are now in a decade that will see gathering concern about climate change and resource depletion. We have also reached a point where government intervention and consumer demand are provoking business to make significant changes in their business models. We can expect to see innovation coming out of cleantech and that makes the sector a place for investors to focus their attentions.

Many in the environmental movement once regarded admiring Wal-mart as heresy. But over the years I have gradually come around to appreciating the commitments by the company towards sustainability: encouraging employee diversity, slashing its CO2 emissions and reducing waste, to name a few big ones.

The publication last summer of its Sustainability Product Index saw the retail giant raise its game. The Index comprised 15 questions it was asking of its suppliers – all 100,000 of them. You’d think that 15 questions would be relatively straightforward: yes or no in many cases. The deliverable will be detailed information at the product level, which will support the creation of a lifecycle database for a wide range of consumer products sold by Wal-Mart.

I’ve been trawling around to see which companies have reported their responses: they are under no obligation to do so, but if you could prove you were doing the right thing wouldn’t you?

So, here’s to Nortel – good on you and to Wilson Korol, who has been leading sustainability at Nortel (losing him to Avaya at the start of this year to work on green/sustainability business over there will be loss, but he leaves a sound legacy). Here is Nortel’s response to Wal-Mart in full.

Energy and climate: Reducing energy costs and greenhouse gas emissions

1. Have you measured your corporate greenhouse gas (GHG) emissions?

Yes, Nortel has measured our global GHG emissions for a number of years.

Material efficiency: Reducing waste and enhancing quality

1. If measured, please report the total amount of solid waste generated from the facilities that produce your product(s) for Walmart for the most recent year measured.

Nortel has outsourced manufacturing, and does not have solid waste metrics from supplier locations. The suppliers tend to make equipment for a variety of other companies as well, which makes delineating the waste production for Nortel-specific products difficult. However, Nortel does track solid waste generation as part of our quarterly Environment, Health and Safety metric collection process from locations owned or operated by Nortel. For 2008 Nortel managed 6,690.62 tonnes of solid waste. Of that total, 4,805.86 tonnes were recycled and 1,794.65 tonnes went to landfills, yielding a recycling rate of approximately 72%.

Natural resources: Producing high quality, responsibly sourced raw materials

1. Have you established publicly available sustainability purchasing guidelines for your direct suppliers that address issues such as environmental compliance, employment practices and product/ingredient safety?

Yes, Nortel has a Code of Conduct for its suppliers. Nortel also has a Corporate Social Responsibility (CSR) Supply Chain Program. This program incorporates criteria to evaluate and promote leadership in areas of corporate responsibility, including social, labor, environmental, health and safety aspects. The CSR Supply Chain Program requires top-tier suppliers to participate in a series of questionnaires. Based on the results of the initial questionnaires, suppliers may be required to participate in further interviews or on-site audits to determine if they are operating their business in a manner which supports the Supplier Code of Conduct, Nortel standards and local legal standards.

People and community: Ensuring responsible and ethical production

1. Do you know the location of 100 percent of the facilities that produce your product(s)?

Nortel has a robust supplier management program which reviews a significant percentage of the direct suppliers that produce Nortel products. Of course, our supply chain has many layers and our supply management review process and CSR Supply Chain Program focus on the suppliers that directly supply our operations and product manufacturing.

Designer Paul Smith has come up with a typically Paul Smith way of tackling trash: treat its disposal with humour and hopefully it means less on the streets. His design is as eye-catching as it is practical. These reactive racing green coloured rabbits show their appreciation each time a piece of rubbish is tossed in.

When a person approaches the bin, a sensor in the hoop reacts and the rabbit’s ears flash away. The bins were showcased at The Design Museum before two were installed in public spaces in Covent Garden and Holland Park. Let’s hope we see more in London soon.