As another alternative to assuming simple, we could assume an elaborated counterfactual account of causation. Following Lewis (2000), let us tentatively assume that C influences E if and only if it is the case that if C had not occurred at all, or had occurred at a different time from the time that it actually did occur, or in a manner different from the manner in which in actually did occur, then E would not have occurred at all, or would have occurred at a time different from the time that it actually did occur, or occurred in a manner different from the manner in which it actually did occur. For short:

Elaborated: C influences E if and only if how, when or whether C occurs makes a difference for how, when or whether E occurs.

The reason why we assume elaborated tentatively is that this analysis requires an adjustment in order to fully capture Lewis’s account. If the influence C exerts on E is minuscule, Lewis argues, we might be justified in neglecting this influence and conclude that C does not influence E enough to count as a cause. I will soon get back to this issue.

Also following Lewis (2000), let us further assume that causation is the ancestral, or transitive closure, of influence:

C causes E if and only if there is a causal chain leading from C to E, where a causal chain is a sequence of causal influences.

This means that if C influences D, and D influences E, then C causes E, and this is true even if C does not influence E. In the most trivial case where C influences E directly, C does of course cause E. The transitivity of causation has implications for the question of whether a single drive causes climate change related harm. I will return to this issue in section seven.

If we abandon simple in favour of elaborated, we must conclude that a single drive influences global warming, and therefore that it causes global warming. The emissions produced by such a drive influence how and possibly when global warming occurs; global warming will be the same event, but it will come in a slightly different version – it will occur in a slightly different manner or at a slightly different time – given the addition of these extra CO 2 molecules.

Still, it seems wanting to say that infinitesimal differences in the manner in which global warming occurs (which and how many CO 2 molecules that re-emits photons towards the earth, for example), or the minuscule difference in the timing of global warming (that it occurs a fraction of fraction of a second earlier) would turn one version of this event into another. The event of global warming is not that fragile, to use Lewis’ words. Lewis (2000) considers a similar problem in relation to bottle shattering, and admits that our tentative version of elaborated might be too promiscuous in assigning causes. He writes:

By the law of universal gravitation, a distant planet makes some minute difference to the trajectory of Suzy's rock, thereby making a tiny difference to the shattering of the bottle. So by adopting the fragility strategy, in whichever form, we open the gate to a flood of spurious causes. (Lewis 2000: 188)

This problem becomes especially acute when we realise that also the gravitational force of Billy’s rock might influence the bottle shattering in some minute way, whereby we get the undesired result that Billy’s throw in fact caused the bottle shattering.

To counter this problem, Lewis argues that while Billy’s throw might exert some tiny influence on the bottle shattering, Suzy’s throw influences the bottle shattering to a much greater extent. If Suzy’s rock would have been a little heavier, or if she would have thrown the rock a little sooner, the bottle shattering would have changed correspondingly; but if we would similarly alter Billy’s throw, the bottle shattering would be (almost) unchanged. On this basis, he argues that if the influence of one event is minuscule enough compared to the influence of some other event, we are entitled to neglect it. Lewis again:

Well, these differences made by spurious causes are negligible; so, surely, we are entitled to neglect them. Just as it is right to say that a box contains nothing when, strictly speaking, it contains a little dust, so likewise we are within our linguistic rights to say that Billy's throw made no difference to the shattering when, strictly speaking, its gravitational effects made an imperceptibly minute difference. (Lewis 2000: 189)

For this reason, a more accurate and elaborated version of elaborated is:

Elaborated*: C influences E if and only if how, when or whether C occurs makes enough of a difference for how, when or whether E occurs.

If we assume elaborated*, it seems that a single leisure drive might not cause global warming after all. The differences in global warming produced by one single drive are not significant enough to turn one version of global warming into another. There are substantially larger emissions than those produced by a single drive, for instance those made by large coal-fired powerplants (given that we do not individuate these emissions events too much). Why would not such an emission count as a cause of global warming, while the emissions from a single drive would not? Similarly, if we consider my decision to go for a single drive, the effects such a decision has for global warming (assuming that my decision in fact makes me go for such a drive) makes much less of a difference for global warming than a governmental decision to allow for offshore oil drilling (given that such a decision results in actual drilling and, in the longer run, lower fuel prices and more emissions of greenhouse gases from burning fossil fuels). It seems that considerations such as these might explain a common position with respect to global warming: what I do as an individual does not cause global warming,Footnote 15 but that governmental decisions and the decisions of most large companies do. As we have seen, this is a view that Kingston and Sinnott-Armstrong subscribe to (albeit for a mistaken reason, see section 3).

Still, in some circumstances we might have reasons to consider even minuscule differences in how and when an effect occurs. Lewis again:

[I]f for some strange reason we did attend to these negligible differences, would we not then put ourselves in an unusual context where it was right, not wrong, to count all the things that make negligible differences as joint causes of the effect? (Lewis 2000: 189)

The fundamental question then becomes whether we are in a context where we have reasons to consider also minuscule differences in how and when global warming occurs. One problem for settling the issue whether a single drive causes global warming is that the only guidance Lewis gives to decide this is that an event does not count as a cause of a certain outcome if it influences this outcome to a much lesser extent than some other event. However, when it comes to global warming, there is no natural place to draw the line between the emissions that are too small to count as causes, and those that are large enough to do so. In joyguzzling, there are not only two potential causes as in bottle shattering, one which greatly influences the outcome and one which only influence the outcome to a minuscule extent, but a whole range of potential causes of different sizes. Single drives could be longer or shorter, there are companies emitting less and companies emitting more. The decisions of smaller governments have less of an impact on global warming than the decisions of larger ones, etc. We could choose to draw the line at one particular level, saying that all smaller emissions do not count as causes and that all the larger ones do, but wherever we draw the line, there will be some arbitrariness about the choice. This means that it is indeterminate whether a single drive causes global warming, and this indeterminacy is due to conceptual inexactness. Our concept of global warming does not univocally set the level of specification of how and when this event occurs, and given the circumstances there is no natural way to specify this level. Elaborated* paired together with the guidance Lewis provides for deciding when a potential cause makes enough of a difference do not help us settling the matter.

This might not be the end of the matter. Apart from the considerations Lewis suggests to be relevant for causal evaluations, other considerations have bearing on the matter.Footnote 16 There are at least two further reasons in favour of thinking that a single drive causes global warming. First, if we do not consider a single drive to cause global warming, we get an explanatory deficit. Hiller’s question re-emerges. If emissions on the level of a single drive do not cause global warming, then what does? Are we dealing with an uncaused effect? If we only consider emissions on the scale of those produced by coal-fired coal powerplants to cause global warming, a substantial amount of global warming would be left unexplained.

Second, whether an emission on the level of a single drive is too small to count as a cause of global warming (climate change, etc.) or not might be a normative issue. It might turn out that a vital part of the best way to thwart global warming (climate change, etc.) would be if each individual did his or her best to decrease his or her emissions of greenhouse gases. In that case, we have a normative reason to consider global warming to be a fragile event; that is, we have a normative reason to think that also minuscule differences in how and when global warming occurs makes this event to come in a different version.Footnote 17

Considering another of Sinnott-Armstrong’s arguments might elucidate these points. He makes the following comparison between going for a leisure drive and pouring a quart of water in a river:

Flood: Global warming is more like a river that is going to flood downstream because of torrential rains. I pour a quart into the river upstream (maybe just because I do not want to carry it.) My act of pouring the quart into the river is not a cause of the flood. Analogously, my act of driving for fun is not a cause of global warming. (Sinnott-Armstrong 2005: 299)

Sinnott-Armstrong is however wrong in assuming that these cases are analogous. To begin with, in flood there are only two potential causes: the torrential rain and my pouring a quart of water into the river. Therefore, we can safely conclude that my act of pouring the quart of water into the flood did not cause the flood if we assume elaborated* and follow Lewis’ guidance. The torrential rains influence the downstream flood to a much higher degree than my pouring quart of water into the flood. Had the torrential rains occurred at a different time, in a different manner or not at all, the flood would have changed correspondingly. However, had I refrained from pouring a quart of water into the river, or poured it at a different time or in a different manner, the flood would have occurred in more or less the same manner and at the same time. Therefore, we are entitled to neglect my act of pouring water; this act is analogous to Billy’s throw. However, in in joyguzzling, there are loads of potential causes with varying degree of influence.

Secondly, in flood, the explanatory deficit if we disregard the influence of my pouring water into the river is negligible. However, in joyguzzling, if we disregard each individual drive as not being a cause of global warming, it seems that we cannot fully explain what caused this phenomenon.

Thirdly, if we seek to prevent future floods from occurring, it suffices to concentrate on how to prevent future torrential rains to cause floods. Since the small amount of water I contributed to the flood is negligible, we are allowed to disregard this contribution. Things would have been different if the flood was caused by billions of people each pouring a quart of water into the river. In such a case, we would have a reason to consider also minor contributions. Likewise, if we seek to prevent as many climate change related harms as possible, it might not suffice to concentrate on events that influence these harms to a great extent (such as emissions from huge coal-fired powerplants and some political decisions). Instead, we might also have reasons to consider more minor emissions, such as those produced by a single drive.

I will leave it unsaid whether these considerations give us decisive reason to conclude that a single drive in fact do cause global warming. Instead, I will rest with the conclusion that if we assume elaborated* and follow the guidance Lewis gives for deciding when a potential cause makes enough of a difference to count as a cause, it is indeterminate whether a single drive causes global warming. Some might balk at this conclusion. Towards the end of the paper, I will offer some considerations that hopefully make it more palatable.