One said that driving at 50 miles an hour saves 10% of fuel compared to 70mph; the other showed money tinkling out of a car’s exhaust pipe at a red traffic light and exhorted drivers to turn their engines off when stationary.

These taxpayer-funded advertisements are a ripe example of green hypocrisy, given the quantity of public money that goes into building faster roads in Scotland.

The Scottish Government recently built one of the world’s most expensive pieces of motorway – an extension to the M74 – against strong local opposition, through a housing scheme to the east of Glasgow. The road raises noise and pollution for local residents to unhealthy levels and significantly reduces the quality of their environment. But it enables drivers who don’t live in the area to traverse it at 70mph on yet another fast motorway through the environs of Glasgow, a city already strewn with urban motorways.

And despite its carbon target the Scottish Government remains committed to dualling the A9 from Perth to Inverness, though I have rarely been in a queue of cars on that road that went slower than 50mph.

Even in Edinburgh the city council continues to favour speeding cars over slow pedestrians.

At many junctions pedestrians have to walk hundreds of feet corralled by metal cages to designated crossing points away from their direction of travel.

Such pedestrian-unfriendly street design actively discourages walking but it makes the driver feel safe while he moves, legally, at speeds up to, and often above, 30mph.

Walking in Edinburgh is so dangerous that I warn foreign students to exercise extreme caution when crossing uncontrolled junctions where, according to the Highway Code, they have right of way.

And this is to say nothing of cycling. Many of my friends have bicycles but few of them are prepared to take the risk of pedalling to work on Edinburgh’s car-laden streets. Cycle lanes – where they are available – are treated in cavalier fashion by road designers and drivers alike.

To take an example close to my office, there used to be a cycle lane along George IV Bridge to the Royal Mile. But when the new Missoni Hotel was opened earlier this year the cycle lane was ditched in favour of a publicly provided parking bay for the hotel and two lanes for motorists.

It is not just in the central belt that we see green hypocrisy on the roads.

There is a new piece of road on the A832 in the Western Highlands from Kinlochewe to Achnasheen that is wide, smooth and on sweeping bends banked like a race track. If you like fast roads it is fabulous.

And whereas the old single-track version did not permit speeds above 50mph I have been passed by people driving at 90mph on the new highway. The European Union helped to pay for the road. And the condition for European investment is that roads must be straight and fast.

This is because the European Commission believes straight fast roads are the key to economic growth, and that economic growth is the way to advance human wellbeing. And so wherever the EU spreads its largesse in the form of aid – in the developed and developing world – fast, straight road-building remains its first infrastructure priority, even though the EU, like the Scottish government, says it wants to “cut the carbon”.

With all this public money – from Europe, from local and devolved and UK taxes – being poured into enabling and encouraging petrol-powered speed, does the Scottish government really imagine that a few billboards and TV advertisements will reduce Scotland’s vehicular carbon footprint? The most expensive bit of public relations for vehicular speed in Britain is Jeremy Clarkson’s Top Gear programme, on which Clarkson and his mates promote speed as the ultimate thrill.

And this programme is made and screened by Britain’s publicly-funded broadcaster, the BBC.

The trouble with green hypocrisy is not only that it is a misuse of tax-payers’ money but that it also brings the conservation cause into disrepute.

A recent report by the Institute for Public Policy Research revealed that many people think exhortations to low-carbon living are hypocritical, and that the problem of climate change is too big for individual actions to make a difference. But if the government sponsors adverts that are clearly telling people to cut the carbon, while ministers and civil servants build public infrastructure to encourage more carbon emissions, is it any wonder people think environmentalists are hypocrites?

Another government advertising campaign exhorts householders to “switch off” the lights. Again the campaign is directed at cutting the carbon.

But the Department for International Trade and Development has invested £90 million of taxpayers’ money in oil and gas projects in the developing world since 2000. The World Bank – which is funded in part by the UK government – invested $4 billion in fossil fuel extraction in the same time period. And the World Bank loaned $450 million to the Tata Group for the building of one of the world’s largest coal-fired power plants at Mundra, Gujarat, in India. The power station’s emissions will outweigh the carbon-cuts of every green-minded citizen in the UK. But it is paid for in part with our taxes.

There is a word for advertising that promotes sustainability by organisations that don’t, and it is greenwash.

And Scotland’s biggest company, the Royal Bank of Scotland, is even better at this than the UK or Scottish governments. Last year it issued a glossy leaflet entitled RBS And The Environment in which it claimed that it was “financing the transition to a low carbon economy” and that it only lent to fossil fuel projects that “conform to the highest international and environmental standards”.

However, in the first six months after it received an injection of £30bn of public funds in October 2008, RBS invested £10bn in fossil fuel ­extraction and energy ­production, and less than a quarter of this sum in renewable energy. And through its subsidiary ABN-Amro it continues to lend considerable sums for oil extraction from the Alberta Tar Sands.

The ­extraction of oil from the tar sands involves significant pollution not only of the local environment but of the atmosphere. Annual greenhouse gas emissions from tar sands extraction are higher than the annual emissions of 147 countries. And water pollution in the area is causing cancers to First Nation peoples and in fish.

On October 20 this year, the High Court in London heard a legal challenge by three British organisations – the World Development Movement, Platform and People and Planet – to the UK Treasury concerning its refusal to take a more active role in RBS in the light of its 70% majority ownership of the company. The UK government’s position is that it does not have a duty – as the bank’s principal owner – to encourage the bank to behave in line with publicly-stated policy with respect to reducing UK and global greenhouse gas emissions. And so this publicly-owned bank continues to take our money – from bank accounts and taxes – and invest it in increasing fossil fuel extraction. But the British Prime Minister at the same time says he is going to the Copenhagen Climate Conference in December to “save the world” from runaway climate change.

The problem of government and corporate greenwash goes to the heart of what prevents the transition to a more sustainable economy. Scotland has embraced a noble carbon emissions reduction target of 42% by 2020 but current policy initiatives cannot deliver this.

This is because governments, corporations and powerful supranational bodies such as the European Commission and the World Trade Organisation remain committed to economic growth, growth in consumption, and growth in mobility of people, goods and services as core policy goals. But growth without limits is not making us happier. Quite the opposite. Research shows that the sense of wellbeing in Britain has declined over the last 30 years at the very time when the country has been more focused on economic growth than on other policy goals, such as reducing inequality. This is despite the fact that reducing inequality has a far greater impact than economic growth on the health and wellbeing of rich and poor alike, as Richard Wilkinson’s recent book The Spirit Level reveals through a range of significant national and international data.

Inequality is also at the heart of the moral urgency of climate change. Those nations – the USA and Canada, the EU and former Soviet Block countries – which have produced the greatest quantities of carbon since the Industrial Revolution are those which are least affected by the extreme weather occasioned by global heating. On the other hand the victims of extreme weather – such as the floods in the Philippines earlier this month or the continuing extreme drought in Kenya – are still largely agricultural and emit carbon at a small fraction of the rate of the industrialised countries.

Confucius, the great Chinese philosopher, taught that a ruler who wants to encourage the people to lead a virtuous life must lead by example.

Aristotle taught that in order for citizens to learn the virtues of temperance and justice they need training in virtuous behaviour through the laws and rituals of the city. Scotland is led and ruled by a professional class whose behaviour and words are not in harmony, and I include myself in this.

Research reveals that professionals consume on average three times as much carbon as ordinary citizens in their work-related travel. They also mostly live in larger than average houses, buy more clothes and electronic goods than other citizens, and fly overseas more frequently for conferences or holidays.

Hypocrisy – doing one thing and saying another – is according to another great teacher, Jesus Christ, a spiritual and not just a moral problem for it corrupts and dishonours our very humanity. The Archbishop of Canterbury, Rowan Williams, spoke in similar vein in a recent address on climate change in Southwark Cathedral.

He suggested that the ecological crisis is a moral and social crisis, and not just a set of scientific and technical problems. Current ecocidal patterns of living are encouraging us to live inhumanly and in ways that threaten the limits of the planet to resource growth and absorb waste.

Corporate and public policy commitments to growing consumption and growing mobility encourage us to neglect the “web of life” and the interconnections between us, and between us and the Earth, that physically and psychologically sustain us. And these commitments are of a piece with attempts to resolve the financial crisis without looking at the interconnected causes of that crisis, and of the ecological crisis. Unchecked economic growth, Rowan Williams suggests, is isolating us from one another and from the planet.

Looked at in this way the actions needed to address climate change offer opportunities for rethinking the nature of human life and the character of human as well as ecological wellbeing. Growing and eating food locally, and carefully composting or recycling our waste will put us back in touch with the seasons, and the land around us, as well as reducing the footprint of air-flown and supermarket food.

Finding a better balance between time spent earning money to buy things such as cars and foreign holidays and leisure to reconnect with the communities and places in which we live will heal our psyches and so help us to recover from our addiction to consumption, as well as to care for the Earth.

Similarly reducing our own personal mobility by refusing to fly, and by getting out of our cars, will put us back in touch with the seasons as we walk or cycle through the leaves, and in sunshine and rain.

And encouraging places in cities where walking and cycling, and not driving, are the dominant behaviours will also help recreate a sense of community, of neighbourhood, and so put us back in touch with each other as well as with the earth.

In this approach doing the right thing by the Earth also turns out to be about doing the right thing by each other. And until government and policy-makers learn to reconnect the two they should exercise a self-denying ordinance on greenwash adverts.

Michael S Northcott is professor of Ethics at University of Edinburgh His book A Moral Climate: The Ethics Of Global Warming is published by Darton, Longman and Todd