I get a lot of correspondence accusing the BBC of bias in its climate change coverage.

While these readers agree that the BBC is biased; what they don't agree about is in which direction it's biased.

Too much "scepticism", or not enough? In the pay of the oil barons, or told what to think by "Europe"? Too scary, or not scary enough?

All these accusations turn up as regularly in my mailbox as they do for my colleagues and in the comments section of this blog and others.

Regular readers of this blog will know that I've tried to steer discussion away from "BBC bias" in months gone by, mainly because I think what's happening "out there" matters more than what's happening "in here".

Whether the Greenland icecap is disintegrating, why biodiversity loss is not being curbed, why industrial fishing is not more efficiently regulated - these are surely bigger questions to ask and more interesting topics for an environment forum than endless debates about BBC reporting.

So you might ask why I'm raising the issue now.

There are two reasons: one is that in the run-up to the UN Copenhagen summit, climate change is moving ever closer to the centre of the political stage, and readership and scrutiny of our coverage is bound to escalate - and I wanted to get this train of thought done and dusted before we reach Copenhagen, because there's going to be no time to discuss it then.

The second reason is that I'd like to respond to a recent blog post by the Daily Telegraph's Damian Thompson, who reported what he described as a "U-turn" in the BBC's climate coverage in an article by my colleague Paul Hudson last week: "Whatever happened to global warming?"

Anyone who monitors BBC coverage regularly will see, first of all, that we do not have and have never had a line on the issue:

We covered the Stern Review when it was published, reporting what it contained and analysing what it meant. We examined it critically and talked to economists who didn't rate it as a piece of work.

We reported the UK government's Climate Projections, which purport to provide a local-level picture of climate change in the future - and reported why some scientists reckoned that the projections couldn't be reliable.

We reported pieces of science suggesting that sea levels would rise higher than the Intergovernmental Panel on Climate Change projected, and pieces of science forecasting there would be no net warming over the next 10 years.

Within the BBC, there are many different people covering climate change.

On this website, you can read articles relating to the issue written by Jonathan Amos, Tom Feilden, Pallab Ghosh, Roger Harrabin, Matt McGrath, James Morgan, Sarah Mukherjee, James Painter, Paul Rincon, David Shukman, Susan Watts - that's just a selection - and by Paul Hudson, and by me.

These days, the issue is covered by journalists with expertise and backgrounds in science, in business, and in Westminster politics, as well as by those with expertise in one particular region of the world.

It's also worth making the point that, as a general rule, the BBC allows the correspondent to identify what the story is. You are the person on the ground who's done the research - it's your field of expertise - and so, by and large, you get to decide what's important about the story and how it should be told.

That's not to say that editors don't scrutinise and shape coverage - they do - but they don't dictate it.

What are we accused of? Here's an example:

A few weeks ago, the US National Snow and Ice Data Center announced that this year's summer ice minimum had not fallen below those of the last two years, but that the overall longer-term trend was still downwards.

Given the constraint that our news headlines have to be between 31 and 33 characters long, I thought "Pause in Arctic's melting trend" was a pretty decent effort, encapsulating both the immediate finding and how it sat in the longer-term picture.

Not a bit of it. It attracted complaints of bias both because "there is no long-term melting trend" and because "it isn't a pause or any such thing": perfect symmetry.

A headline can't be biased in both directions at once. Any bias here has to be in the eye of the beholder.

So here's the nub. In the run-up to Copenhagen, you're not all going to agree with everything the BBC writes or broadcasts - that's impossible. And let's be honest - journalists are not infallible, in the BBC or anywhere else.

But biases and party lines? I don't think so - but please feel free to disagree. So let's have that discussion here, and now.

PS: Another blog post this week - by the Guardian's Leo Hickman - queried why Paul's article appeared as a BBC News website story, when it was first conceived as a blog post.

On this occasion, we commissioned a piece from Paul which in fact overlapped with what he was already doing for the blog.

On most occasions, we'd just link straight to the blog (as we do to this one). But regardless of format, the editorial standards are the same across the News site, blogs and news stories included, as Steve Herrmann describes in a recent post at The Editors blog.