It could be argued that the national weather observations that NMHSs share globally through the WMO coordinated Global Telecommunication System (GTS), which are then assimilated by global NWPs, also provide a public good by improving NWP performance. However, sharing these data primarily results in improved national outputs from the GPCs, thereby most benefitting the country making and sharing the observations. Some observations like upper air soundings may also generate regional benefits. However in this assessment these instances are not considered.

As the focus of this research lies on the supply side and the majority of the costs of GPCs occur in Stage 1, we focus primarily on these stages, however also including GPC costs for training RSMCs and NMHSs to utilize their products (Stage 2). Further, as we are only interested in the additional costs incurred when using forecasting products from GPCs, we must assume the existence of basic capacities under Stages 2-4. While as reviewed in Section 1.4 this should be viewed as a major caveat of this assessment, under the constraints of this research, it would in any case be difficult to extract global NWP-specific costs from Stages 2-4. It is recognized that this assumption is particularly bold in LICs, many of whom lack basic capacities in Stages 2-4.

The costs of GPCs to provide forecasting products to LICs were analyzed using the data gathered from GPCs as described in Section 2.4. Average data ranges of the marginal set-up and running costs of providing the full suite of global forecasting products to an additional country or region were calculated. To estimate the costs of providing global forecasting products to all LICs, these figures are multiplied by the total number of LICs (31 countries). This is a very conservative estimation (resulting in higher than expected costs), as it ignores for example economies of scale when products are provided to regions. The results are shown in Table 3.1.

**_Table 3.1_** _: Summary of costs under conservative assumptions, in 2014 US$._

|**Countries**|**Set up costs (US$)**|**Annual costs(US$)**|
|---|---|---|
|Single LIC|65,700 – 303,800|29,800 – 151,900|
|All 31 LICs|2,036,200 – 9,419,200|924,200 – 4,709,600|

Based on experience, WMO (2013) estimates that the funding requirements for the implementation and sustainability of a SWFDP regional project engaging six NMHSs, one RSMC and three GPCs over five years amounts to about US$3.4 million, averaging US$680,000 per year (assuming no costs for infrastructure). Scaling up to cover 31 countries (all LICs), this comes to approximately US$3.5 million per year. This assumes that the contributions from GPCs and RSMCs are provided in-kind, which has so far been the case. Comparing to Table 3.1, it is observed that the GPCs’ contributions to SWFDP are of similar magnitudes of cost to the technical cooperation and coordination budget of SWFDP. In other words, the GPCs’ critical role also reflects a substantial financial “donation” with respect to the full cascading system. Full engagement by RSMCs is likely also of a similar cost magnitude, with most RSMCs not accessing sufficient funding to fulfill this role (WMO et al 2013).

# 3.3 Benefits

In order to assess all added value, financial, environmental and social benefits have to be considered through a “triple bottom line” approach (WMO et al 2015). Financial benefits include both reduced asset damage and additional quantifiable economic benefits such as more efficient sectoral production and planning (agriculture, energy, transport etc.). Environmental benefits include improved 12