It was heartening to hear last night that even the most influential economist in the world on impacts of climate change sometimes feels weighed down by the massive global challenge we face.

Nicholas Stern, the former chief economist of the World Bank, former head of the UK Government Economic Service and author of the hugely influential Stern Review on climate change in 2006 was speaking at the London School of Economics – where he now heads the Grantham Research Institute on Climate Change and the Environment.

In the Q&A at the end of Stern’s talk, the Guardian blogger Ed Gilespie asked him how he could be optimistic in the face of contradictory policies by the UK government. Stern confessed that sometimes he could not help focussing on the negatives: “The Russians will cheat, the Americans are not going to give up their SUVs, the Chinese don’t care anyway and the Brits are too lazy to do anything. I can sit in a bar and tell these stories – and I have done – but that doesn’t mean that they are a good basis for action,” he said.

But if we give in to pessimism then we have already failed to solve the climate crisis, he said. “What’s the alternative to optimism? Unless we act as if we can sort this out you might as well just get a hat and some sun tan lotion and write a letter of apology to your grandchildren. The only way we can think of going forward is to try to make the best of a bad starting point.”

“The one way of guaranteeing to fail is to assume that we will,” he added.

Stern’s description of the scale of the problem was characteristically uncompromising – “this is the biggest market failure the world has ever seen”, “the world is more risky than I articulated [in the Stern Review]”, we risk a “transformation of the planet”. But the talk itself, which was to promote his new book, A Blueprint for a Safer Planet, had an upbeat tone. His message was that we have a pretty good idea what the solutions are and what we need to avoid. New technologies like better renewable energy are vital, energy efficiency is a must, deforestation has to be halted and massive fiscal stimulus packages designed to deal with the economic crisis can and should transform the world economy with a greener hue.

In particular, Stern said the world has to get a move on with carbon capture and storage. Currently around half the world’s electricity comes from burning coal so we have to find a way of doing that without releasing stacks of CO₂. “If coal is going to be used, the only response – because it is the dirtiest of all fuels – is that we have to learn how to do carbon capture and storage and we have to learn how to do it quickly on a commercial scale,” he said.

If CCS won’t work on a large scale we have to find out quickly. “If we can’t then it’s plan B and plan B will be more expensive probably,” he added.

He repeated his call that the proposed Kingsnorth coal-fired power station should not go ahead unless it is fitted with CCS. “We can’t ask India and China to use new clean coal technologies if we are not prepared ourselves to demonstrate that they work and share those technologies,” he said.

The UK government’s announcement on Kingsnorth is imminent. It remains to be seen whether it is listening.

• We will be podcasting a recording of the event. I’ll post a link in the comments when it is up.

A report from the European Environment Agency (EEA) to be published next month sounds the alarm that most species and habitats across the continent are in poor condition and the risk of extinction continues to rise.

New figures for the UK also show that even the most important and rare plants and animals are suffering: eight out of 10 habitats and half of species given the highest level of European protection are in an “unfavourable” condition.

Species at risk in the UK range from insects like the honeybee and swallowtail butterfly, to mammals and birds at the top of the food chain such as the otter and the golden eagle, said the Centre for Ecology & Hydrology (CEH).

The losses threaten to undermine vital ecosystem services like clean water and fertile soils, which underpin both quality of life and the economy, said Jacqueline McGlade, the EEA’s executive director.

“Much of our economy in Europe relies on the fact we have natural resources underpinning everything,” McGlade told the Guardian. The losses of wildlife and habitat are a threat to being able to live sustainably within the enviroment in the future, she said. “Some of the losses are irreversible.”

McGlade will present findings from the agency report at a major conference next week called by the European environment commissioner Stavros Dimas. He is worried that the European commission has failed to meet a pledge to halt biodiversity loss by 2010, and recently warned “the loss of biodiversity is a global threat that is every bit as serious as climate change”.

“The reasons that we are losing biodiversity are well known: destruction of habitats, pollution, over-exploitation, invasive species and, most recently, climate change,” Dimas will tell the conference in Athens. “The compound effect of these forces is terrifying.”

At another high-level conference in London on Wednesday, organised by the CEH, leaders from business, government, academics and NGOs will warn that ecosystems underpin human lifestyles from air, water and food to resources for industry.

Professor Lord May of Oxford, a former government chief scientific adviser and president of the Royal Society, said: “Our massive and unintended experiment on the planet’s reaction to unsustainable levels of human impacts is approaching crisis point. The future is not yet beyond rescue, provided we take appropriate action with due urgency.”

The EEA report says although there have been some conservation successes, including halting the decline of common songbirds, the “overall status and trends of most species and habitats give rise to concern”.

Figures for the habitats and species awarded special protection under the EU habitats directive reveal that across 40 countries of Europe and the former Soviet Union, 50-85% of habitats and 40-70% of species were in an “unfavourable” condition, and many more could not be assessed because of a lack of information.

Across Europe, the biggest declines from 1990 to 2000 had been for bogs and fenland, heathland and coastal habitats. Woodland, forests and lakes had grown, but these increases were dwarfed by the biggest habitat expansion, which was “constructed, industrial, artificial habitats”.

Populations of some European common birds stopped falling in the 1990s, but all groups of birds had fallen in numbers since 1980, and other species groups like butterflies, amphibians and pollinating insects had declined dramatically, said the report.

The report notes that habitats and species in the habitats directive were chosen because they were under threat, and so were harder to conserve.

“Ecosystems generally show a fair amount of resilience,” it adds. “Beyond certain thresholds, however, ecosystems may collapse and transform into distinctly different states, potentially with considerable impacts on humans.”

Reforms to be put to the conference in Athens include better management of protected areas, which now make up more than 17% of the European Union territory; targets for economic sectors, such as transport, to ensure they do not have a negative impact on the environment; and more work on putting a “value” on ecosystem services so conservationists can argue their case against developers, said McGlade.

“This is not about putting a price on everything, it’s a value. This will transform the discussion because somebody can say ‘you’re eating away at our capital – grassland’, or whatever the landscape or species is.”

In a statement, Defra, the UK environment department, said the government fully supported strong international targets, but said many conservation schemes were working.

“For example, England’s Sites of Special Scientific Interest are in better condition than ever at 88.4% in favourable or recovering condition compared with 57% in 2003,” it added.

Globally, last year’s annual “red ist” of endangered species from the IUCN conservation organisation warned that the world’s mammals face an extinction crisis, with almost one in four of 5,487 known species at risk of disappearing forever.

Region 486 that unleashed a record flare on the sun. Photograph: NASA/Getty Images

The sun’s activity is winding down, triggering fevered debate among scientists about how low it will go, and what it means for Earth’s climate. Nasa recorded no sunspots on 266 days in 2008 – a level of inactivity not seen since 1913 – and 2009 looks set to be even quieter. Solar wind pressure is at a 50-year low and our local star is ever so slightly dimmer than it was 10 years ago.

Sunspots are the most visible sign of an active sun – islands of magnetism on the sun’s surface where convection is inhibited, making the gas cooler and darker when seen from Earth – and the fact that they’re vanishing means we’re heading into a period of solar lethargy.

Where will it all end? Solar activity varies over an 11-year cycle, but it experiences longer-term variations, highs and lows that can last around a century.

“A new 11-year cycle started a year or two ago, and so far it’s been extremely feeble,” says Nigel Weiss of the University of Cambridge. With Jose Abreu of the Swiss Federal Institute of Aquatic Science and Technology in Dübendorf and others, Weiss recently predicted that the long-term solar high we’ve been enjoying since before the second world war is over, and the decline now under way will reach its lowest point around 2020. Their prediction is based on levels of rare isotopes that accumulate in the Earth’s crust when weak solar winds allow cosmic rays to penetrate the Earth’s atmosphere.

There’s even a chance, says Weiss, that we might be heading for a low as deep as the Maunder minimum of the 17th century. Either side of that trough, Europe shivered through the Little Ice Age, when frost fairs were held on the Thames and whole Swiss villages disappeared under glaciers. So should we expect another freeze?

Those who claim the rise in temperatures we’ve seen over the last century are predominantly the result of intense solar activity might argue that we should, but they’re in the minority. Most scientists believe humans are the main culprit when it comes to global warming, and Weiss is no exception. He points out that the ice remained in Europe long after solar activity picked up from the Maunder minimum. Even if we had another, similar low, he says, it would probably only cause temperatures on Earth to drop by the order of a tenth of a degree Celsius – peanuts compared to recent hikes. So don’t pack your suncream away just yet.