A man on a boat once said

Hearken; Behold, there went out a sower to sow:
And it came to pass, as he sowed, some fell by the way side, and the fowls of the air came and devoured it up.
And some fell on stony ground, where it had not much earth; and immediately it sprang up, because it had no depth of earth:
But when the sun was up, it was scorched; and because it had no root, it withered away.
And some fell among thorns, and the thorns grew up, and choked it, and it yielded no fruit.
And other fell on good ground, and did yield fruit that sprang up and increased; and brought forth, some thirty, and some sixty, and some an hundred.

— Mark 4:1-8 (KJV)

In the Synoptic Gospels, a certain wise teacher clarifies to his disciples that the above introduction to his lakeside sermon was no mere lesson in agricultural practice, but an elegant way of illustrating to the gathered crowd the primacy of a believer's state of heart and mind in determining their capacity to prosper from his gospel.

As evidenced by the name of this blog, it is the second scenario described by Jesus which is of particular interest to me. I pray that I have his blessing to co-opt The Parable of the Sower as a far more prosaic analogy: the importance of considering the condition of the Earth in the potential use of large-scale forest plantation as a form of biogeoengineering. The potential of afforestation and related technologies to sequester CO2 from the atmosphere, thereby mitigating climate change is the subject of a growing body of scientific literature. Indeed, the IPCC stresses that these methods " play a major role in many mitigation scenarios" (AR5 Sythesis Report, Box 3.3). It would not therefore be wholly absurd to suggest that the 21st century will see the establishment of many new forests in the fight against climate change.

To innocent eyes, it would seem blindingly obvious that any proposition which involves planting more trees must be A Good Thing. Personally, I'm not so convinced. Of course, like (almost) any university student found wondering in the halls of their Geography department, I desire little more than to see the global community take strong, effective and co-ordinated action to order to avert a catastrophic warming of our home planet. Nevertheless, I feel urged to question whether our current understanding of climate science has yet reached a level of maturity at which humanity can begin to safely engage in the extensive modification of the Earth System.

What is the likelihood that biogeoengineering, effected without due consideration for any issues that may arise - environmental, technological and social - will have grave unintended consequences? If short-sighted economic thinking is allowed to dominate the discourse, it appears to me to be an inevitability. Even the ostensibly low-risk technologies related to afforestation, though appearing fruitful at first, may prove over time to be of little lasting value: much like the seed sown on stony ground.