BBC VIEWPOINT by Chris Rapley
Some enviromental scientists argue that the global population is higher than the Earth can sustain, and suggest that solving environmental problems such as climate change is going to be impossible without tackling the issue.
Human effect on land cover, the water cycle, the health of ecosystems, our release of other chemicals into the environment, our massive transport and mixing of biological material worldwide, and our unsustainable consumption of resources all interconnect and add up to the collective "footprint" of humankind on our planet's life support systems.
The consequences extend to the ends of the Earth, such as the hole in the ozone layer over the Antarctic, and each is as difficult to predict and as challenging to deal with as the link between carbon emissions and climate.
Although reducing human emissions to the atmosphere is undoubtedly of critical importance, as are any and all measures to reduce the human environmental "footprint", the truth is that the contribution of each individual cannot be reduced to zero.
Only the lack of the individual can bring it down to nothing.
In theory a scientific analysis suggests that optimum number is perhaps 2-3 billion.
In practice, of course, it is a bombshell of a topic, with profound and emotive issues of ethics, morality, equity and practicability.
Top Target Stars for Life Picked
BBC News Science By Paul Rincon
"There are bazillions of stars in the sky to look at, but we can't look at every single one with the scrutiny that we'd like to," said Margaret Turnbull at the Carnegie Institution in Washington DC.
"We have been able to prioritise our search so that we are looking at stars that are most like the ones around which we live. We need to know which ones to spend our telescope time on."
Seti, the Search for Extraterrestrial Intelligence, is an exploratory science that seeks evidence of life in the universe by looking for some signature of its technology.
Astronomers have put together a set of principles - called the Seti principles - that outline what should be done if a signal from an extraterrestrial civilisation is ever detected.
Life's Sweet Stuff
MSN Health by Ross Chainey
National Honey Week focuses on the many health and beauty benefits of the sticky stuff, and the ways in which you can use it as a cheap, all natural substitute to medicine to treat a number of ailments such as colds, sore throats and minor cuts and burns.
Honey, that thick, delicious viscous fluid produced by busy bumble bees from the nectar of flowers was used by the ancient Egyptians in their embalming mixture, the Romans offered it as a gift to the gods, and the Vikings fermented it with yeast.
This sweet stuff was widely recognised by early civilisations for its numerous healing properties, and for thousands of years since it has been used not just as a natural sweetener, but as a medicine and beauty product.
For a start, honey is a much healthier, natural alternative to sugar. So instead of using sugar in tea or baking, add antioxidant rich honey. If you do choose to use honey as a sugar substitute, use less as it's much sweeter than regular sugar.
With its cleansing properties it will feature regularly in detox regimes. Taking honey with hot water and a slice of lemon is a great way to kick-start your day; an energy boost that is much better for you than caffeine.
Honey also comes in useful in a season of colds, coughs and sore throats. A spoonful of honey soothes sore throats, and again taken with a slice of lemon and hot water will fight the symptoms of flu. Surprisingly, honey is also a mild antiseptic, and can therefore be used to keep cuts and burns clean and prevent the wound from becoming infected.