We make decisions today under the shadow of uncertainty with respect to major future events. Global warming, for instance, seems likely to cause us negative income shocks in the future but we cannot be sure of their size. Likewise, imaginable transformative technological change will likely cause positive shocks for some as well as negative ones for others, but most people cannot be sure which will predominate. No person’s individual decision can materially affect the likelihood of such future income shocks because they are driven by uncertain system-wide properties. Nevertheless, we know that such shocks are a possibility. This paper examines with an experiment how such background uncertainty affects a) current individual decision making in social dilemmas and b) our risk tolerance when making investment decisions. This is important because it is often suggested that background uncertainty has been increasing. There are two senses in which this might be occurring. One is that, with global warming and the experience of COVID, we have become more sensitised to the possibility of future negative income shocks than before, with the result that future looks bleaker. The other is that, with the growth of complexity, systemic outcomes have become less predictable in the sense that the perceived variance in possible future outcomes is increasing. We test for how current decision making is affected by both senses of a growth in background uncertainty. We find that the prospect of negative income shock in the future increases pro-sociality in public good and trust game decisions and increases risk tolerance now. The prospect of positive income shock in the future has the reverse effects. A perceived shift in shocks in the negative direction, therefore, ceteris paribus, increases pro-sociality and risk taking. An increase in the variance of future income that preserves the expected mean, however, has no effect. That is, we are risk neutral with respect to how variance in the uncertain future affects our pro-social and investment decisions today.