|I have this horrible suspicion that he's trying to be funny.|
A better answer is that Christianity is more properly focused on us in our relations with God and other people. Proper stewardship of the earth, though not an irrelevant topic, is quite a bit removed from the “ground zero” of divine revelation and apostolic tradition.
Some Christians are against genetic modification; for instance, a fellow Catholic who contributes frequently to The Distributist Review, John Médaille, opposes GMOs. But I think it’s safe to say that the bulk of Christians who oppose GMOs can and do so without dragging the Lord’s name into it. An argument against GM foods could probably be made from Leviticus 19:19 (“You shall not let your cattle breed with a different kind; you shall not sow your field with two kinds of seed; nor shall there come upon you a garment of cloth made of two kinds of stuff”). However, as I’ve noted elsewhere, Christians aren’t bound to observe the Law of Moses; ritual purity is less important than compassion and avoidance of sin.
For my own part, I’ve not read enough of the relevant literature to take a stand either way. But to slam GMO’s opponents as “anti-science” is both wrong and misleading. Monsanto is the main target, but the agro-biotech giant is also the symbol of corporate regulatory capture of federal watchdog agencies. The fear isn’t of science or technology per se, but rather of “science for hire” — the insidious influence over scientific research wielded by the dreaded, dreadful “one-percenters”.
In “Who Will Control the Green Economy”, the ETC Group asserted that the top 10 multinational seed companies controlled 73% of the world’s commercial seed market in 2011, up from 37% in 1995. The 2000 “Open Letter from World Scientists” argued that the increasing dominance of the global seed market by a handful of companies is accountable for “family farmers [being] driven to destitution and suicide”. “It is on account of increasing corporate monopoly operating under the globalised economy that the poor are getting poorer and hungrier,” the document charges, citing a series in The Economist written earlier that year. Moreover, authors assert, the patents and terminator technologies prevent farmers from saving and replanting. While saving and replanting is a smart cost-saving strategy even in corporate farming, it’s crucial to successful subsistence farming in Third World regions; by introducing terminators that render seed sterile by year’s end, the agro corporations force farms to buy far more seed every year than they would if they could save and replant.
One-percenter monopolization of the world food market is secondary to consumer fears of negative health and biosphere effects of GM crops. Katie Rucke, writing in Mint Press News about growing support for the recent “March Against Monsanto”, alleges, “The substances to be protested carry known health risks such as organ damage, sterility, infant mortality, birth defects, autoimmune conditions, allergies and increased risk of cancer.” She quotes, among others, Josh Castro, an organizer for the March in Quito, Ecuador: “Monsanto’s harmful practices are causing soil infertility, mono-cropping, loss of biodiversity, habitat destruction, and contributing to beehive collapse.”
In fact, there’s quite a bit of controversy over whether there’s sufficient data to substantiate the negative health effects. However, anti-GMO activists regularly point out that much of the positive data is generated by the agro-biotech companies themselves, and that they have financial influence over some of the supposedly independent panels that have attempted to diminish concerns.
For instance, even the relatively unbiased Wikipedia article on the controversy couldn’t help noticing that FSANZ (Food Standards Australia New Zealand) is “a panel of toxicologists funded by Monsanto”. Another article on EFSA (European Food Safety Authority), instrumental in shooting down GMO-critical experiments performed by anti-GMO activist Gilles-Eric Séralini, notes that the EU regulatory body has been accused of basing their conclusions on industry reports and of having members with industrial ties to food, biotech and pesticide companies. This is echoed in the Rucke piece, where she asserts, “Former attorneys for the organization have been appointed to key positions within federal agencies such as the Food and Drug Administration and the Environmental Protection Agency, which are tasked with regulating ‘Big Agriculture’ businesses.” The link leads to a RealFarmacy.com article on a complaint to the EPA that “Monsanto and the biotech industry restrict independent research into the effectiveness and environmental impact of GMO crops.”
Such accusations aren’t without precedent. In the 1990s, as various states’ attorneys general began to mount lawsuits against “Big Tobacco”, a growing feature of those lawsuits was the allegation that the tobacco companies knew about tobacco’s addictive property and deliberately suppressed the information from the public. Part of the multi-state agreement settled between the tobacco corporations and most of the state AGs involved the dissolution of three specific “Tobacco-Related Organizations” whose main purpose was to fund and promote “studies” denying the majority consensus position on tobacco’s negative health effects. I remember distinctly that my father — who died of emphysema in ’02 — received such literature semi-regularly, though he was skeptical of their claims (this was before privacy laws required giving consumers “opt out” power).
Many writers, including physician Peter A. Ubel and science journalist Chris Mooney, envision a world in which scientists have the last say in policy design and enactment. Though probably neither writer would ever say so explicitly, and would deny it if asked, such a governmental structure — a scientocracy — carries with it the implicit assumption that, once scientific consensus were reached, everyone else would shut up and fall in line. This conception grows out of scientism, a neo-positivist Weltanschauung neither articulate enough to be called a philosophy nor ritualistic enough to qualify as a religion, which tends to view scientists as daring, courageous and wise people of inflexible honesty who hold the only opinions worth speaking.
The anti-GMO position, on the other hand, assumes that scientists are just like the rest of us slobs, doing what they do to pick up a paycheck, making the occasional mistake, unwilling to make waves if it threatens their livelihoods, and occasionally willing to subordinate the methodology of their research to the support of specific social agendas. For instance, as RealFarmacy.com reports, “Most of the researchers [who signed the protest to the EPA] withheld their names for fear of being cut off from research, even though these corn-insect specialists don’t necessarily think that GMO crops are a bad thing.” Monsanto’s gantlet of restrictions on independent research is reportedly matched only by their willingness to smear researchers who get unfavorable results.
Again I stress that I’m not positioning myself on GM foods, although I dare say a generalized position could be constructed based on Catholic social doctrine. [In fact, such a position has already been articulated; see Update.] This is simply a warning not to dismiss the anti-GMO position as “anti-science”. If anything, it’s based on a long-standing and (may I say) historically justified distrust of huge corporations.
When the one percent controls the scientific consensus, a scientocracy can only be a puppet regime.
Update: May 29, 2014
It's been awhile since I've read the Compendium of the Social Doctrine of the Church, linked above (but here it is again). It does, in fact, have quite a bit to say about biotech, which I will try to summarize [CSDC paragraph references in brackets]:
In general, the Catholic Church doesn't object to the concept of genetically-modified foods, because nature is "a gift offered by the Creator to the human community, entrusted to the intelligence and moral responsibility of men and women." However, there must be accurate and adequate assessment of the real risks and long-term consequences as well as of the potential benefits.  "A central point of reference for every scientific and technological application is respect for men and women, which must also be accompanied by a necessary attitude of respect for other living creatures. Even when thought is given to making some change in them, 'one must take into account the nature of each being and of its mutual connection in an ordered system'."  The Church goes so far as to say that humans have a positive duty to the environment, to "the preservation of a sound and healthy environment for all." 
"Men and women have the specific duty to move always toward the truth, to respect it and bear responsible witness to it" ; from this principle alone, grounded in the commandment, "You shall not bear false witness against your neighbor" (Ex 20:16; cf. Lv 5:20), we can infer a moral obligation by corporations to be transparently honest in their business dealings, which includes research on their products.
The contribution a company makes to the common good isn't simply in the jobs it provides or the money it generates for the economy, but also in the way it builds and reinforces the common bonds of humanity (solidarity). 
The Church's social doctrine insists on the need for business owners and management to strive to structure work in such a way so as to promote the family, especially mothers, in the fulfilment of their duties; to accede, in light of an integral vision of man and development, to the demand for the quality "of the goods to be produced and consumed, the quality of the services to be enjoyed, the quality of the environment and of life in general"; to invest, when the necessary economic conditions and conditions of political stability are present, in those places and sectors of production that offer individuals and peoples "an opportunity to make good use of their own labour". [345; italics in original]
Individuals and groups who engage in the research and commercialization of biotech must abide by the criteria of justice and solidarity. In dealing with underdeveloped countries, equitable exchange necessarily entails "in the first place" that they take place "without the burden of unjust stipulations."  It could be argued, on the basis of this principle, that strategies which eliminate the capacity to "save and replant" are unfair burdens on family and subsistence farmers, especially if the agro-biotechs aren't doing anything else to contribute to the development of the economy.
Finally, people who write on the issue of GMOs have a duty to the truth as well:
Leaders in the information sector also have an important task, which must be undertaken with prudence and objectivity. Society expects information that is complete and objective, which helps citizens to form a correct opinion concerning biotechnological products, above all because this is something that directly concerns them as possible consumers. The temptation to fall into superficial information, fuelled by over-enthusiasm or unjustified alarmism, must be avoided. [480; italics in original, bold type mine]