*Approach and Methods*

The case studies are based on fieldwork by the authors over an extended period of time, while three PhD students, who are supervised by the authors, have conducted fieldwork more recently. Their work is referenced in the case-studies. The aim of the case studies is to look closer at the combined and often cumulative impact of climate change and other environmental changes as a result of logging activities and other types of resource use.

The description of these case studies is based on ethnographic fieldwork by the authors in the context of various research projects, and their involvement as researchers or consultants in a number of conservation and/or development projects. Fieldwork among the Agta was conducted by the second author for a total of 9 months spread out between 2002 until 2005, which was continued with short, yearly field visits until 2014. Fieldwork among the Orang Rimba was done by the first author in July–August in 1983, from August until December 1985, during short visits of one to three weeks in 1988, 2000, and 2005, and during a joint visit by both authors in 2013. The fieldwork on Siberut was done by the first author from September 1979 until January 1982, from December 1984 until July 1985, and during shorter visits of one to four weeks in 1986, 1988, 1994, 2002, 2004, 2009, and 2013. Fieldwork among the Ngaju Dayak was done by the first author in September–October 2002, May–June 2004, November 2004, June 2005, and July 2011.

The long-term insights presented in this article are derived from this ethnographic fieldwork. The methods used during these fieldwork periods are a combination of participant observation, qualitative interviews, and structured interviews with local informants from the indigenous peoples that we describe, as well as interviews with field officials, missionaries, representatives of NGOs, staff of logging and mining corporations, and development workers. Secondary sources, including company reports, and data from local government offices were also part of this knowledge base. Insights from these primary and secondary sources have been used in combination with the relevant scientific literature.

### **2. Climatic Change in Southeast Asia**

Over the past two decades numerous reports, including those of the International Panel of Climate Change (IPCC), have been published about climatic change in Southeast Asia [15]. The information contained in these reports has also been used to produce Global Climate Model (GCM) outputs in order to be able to assess the impact of climatic change and to suggest options for adaptation measures. In general, the literature about Southeast Asia shows a high level of agreement on observed climate change and its impacts. Of course, there is also substantial variation within the region given the size of the area and the prevailing climatic conditions. It is not the purpose of this article to discuss the wealth of available data in detail, but here we highlight the main trends and projections for the region [16–18].

Differences in rainfall patterns and the occurrence of typhoons predated the present-day climatic changes. In large parts of Southeast Asia, the climate extremes which have been known for a long time, such as El Niño and La Niña, are likely to increase in scope and frequency, leading to higher risks of extended periods of drought as well as heavy rains and therefore floods. Increase in surface temperature has already exceeded 1 ◦C during the 20th century and is expected to further increase depending on future developments. Making general statements about changes in annual precipitation is difficult, as there are substantial differences between and even within countries. In Indonesia for instance, some areas have experienced an increase in rainfall in recent years, while in others it has reduced. This change has not been homogeneous. In the future, the Philippines will most likely be hit by a larger number of typhoons, which might also increase in relative strength, bringing increased amounts of rainfall [19,20].

The impacts of climate change are felt in various sectors. Agricultural productivity is severely influenced by the longer dry seasons caused by El Niño. Increasing sea water temperatures are likely to affect aquaculture along the coasts of the Philippines, Vietnam, and Indonesia. The extensive periods without rainfall are likely to increase the risk of forest fires. This is particularly problematic in the peat land forests of Borneo and Sumatra, large parts of which have recently been drained for establishing commercial plantations, contributing also to biodiversity loss. Heavier and excessive rainfall, on the other hand, may lead to floods, thereby destroying both agricultural land as well as settlements and infrastructure, notably roads and bridges. Human health will be impacted as well: vector borne diseases such as malaria, and dengue fever will be spreading as a result of stagnant water. Availability of drinking water will become a problem during drought periods. Particularly low-lying areas close to the coast may suffer from inundation and salt water intrusion, which will then also threaten agriculture and drinking water facilities. This may be aggravated by sea level rise, predictions for which vary across the region, but which is already threatening parts of Vietnam and Indonesia. Coral reefs will be affected by the rise in temperature [17,19,20].

Many of these phenomena are well-known by now and they have become subject to various policy measures. Examples are the ban on the use of fire as an instrument in forest management or in the process of conversion to other types of land use (to avoid wild fires), the rehabilitation of degraded peat swamp forests (to avoid further drainage) and the reduction of conversion of mangrove forests into shrimp ponds (to avoid coastal erosion and coral bleaching) [17]. A range of management and financial instruments have been designed to cope with these problems, including the Clear Development Mechanisms (CDM), which provide financial means for taking positive environmental action. This includes compensation for not doing particular things, as is the case for REDD+ (Reducing Emission from Deforestation and Forest Degradation, with the addition of biodiversity). This program compensates owners or managers of a forest area for abstaining from logging, or for the additional costs arising from biodiversity conservation [21].

REDD+ has been criticized for its lack of efficacy, which stems from challenges regarding the governance of these schemes and the complex web of agencies, right claimers and other stakeholders involved. In some cases, large scale land acquisitions and efforts to protect the ecosystem through REDD+ strategies may even compete for the same area [21]. Another important point of criticism relates to the additional impacts that these schemes have on indigenous communities' well-being. These impacts are most directly felt with respect to the landscapes, and the plant and animal life on which their livelihood is based. The REDD+ program serves as one of the most important examples of how climate change mitigation measures often limit local and indigenous communities' access to natural resources. Limitations also tend to include prohibitions on shifting agriculture. As a result, food procurement has to change, which often has far-reaching social consequences, including changes in division of labor within communities and households. Knowledge and skills that were essential for traditional tasks, may become less important under such conditions [22–24]. Such experiences should form the basis for reconsidering the way REDD+ projects are being implemented as well as the impact such projects have on local livelihoods [25].

The indigenous peoples inhabiting the tropical lowland forests of Southeast Asia have been faced with large scale changes over the last few decades, of which the ongoing process of climate change is only one. Though some areas were already converted into plantations for cash crops like rubber and palm oil in the first decades of the 20th century, it was mainly in the 1970s and 1980s that the scale on which activities like logging, mining, and conversion took place and became much larger. In combination with more powerful technology (chainsaws, bulldozers, and skidders), the construction of roads facilitated the extraction of other resources like coal, iron ore or minerals. These road networks also facilitated the arrival of people in search of arable land in areas that were often considered as being 'empty land´ [8,26]. As a result of these activities, the landscape of the tropical lowland forests of

Southeast Asia has been described as a mosaic of land use types, in addition to the traditional forms of land use by the indigenous population [27]. When zooming in on individual countries, or even regions within countries, the overall picture of the forests of Southeast Asia is one of massive forest degradation or even deforestation and conversion to plantations. The FAO/UNEP's annual publication on the State of the World's Forests clearly shows this overall trend for regions and countries like the Philippines, Indonesia, Malaysia, Vietnam, and Cambodia [28]. Numerous and more detailed individual country studies confirm this trend. Though there is also a gradual increase in the number of protected areas, as national parks or areas with another conservation status, the contrast with their adjacent areas is getting more and more obvious in terms of the type and quality of the vegetation cover and biodiversity. Increasingly such protected areas become 'islands' without 'bridges', corridors, or connections with other conservation areas [29–31].

Compared to climate change, the impact of the large-scale forest degradation and conversion on the living conditions of the indigenous peoples is, without doubt, much more strongly felt. While the effects of climate change come gradually and may in some cases be hardly noticed by forest-dwelling communities, forest operations carried out by logging and mining companies usually have a more immediate impact with far-reaching long-term consequences. Importantly, in many cases the effects of such operations may aggravate the impact of climate change. For example, the construction of logging roads and the removal of trees results in an open canopy, which intensifies the drying of debris of the logging operations along such roads and on the forest floor during El Niño periods. Forest fires may spread more easily under such conditions, while a lowland tropical rainforest with a closed canopy and without direct sunlight on the forest floor will hardly be susceptible to rapidly spreading forest fire [29].

In the recent scientific and popular literature, as well as in the national and international policy discourse, one can easily get the impression that climate change is by far the most important cause behind the present-day problems faced by all kinds of communities across the region. However, in real life situations, the impacts of forest operations by logging, mining, and agricultural companies, are much more clearly and urgently felt. Moreover, there can be no doubt that deforestation and forest degradation generate vulnerabilities that aggravate the (future) impacts of climate change. These various impacts are thus cumulative and mutually reinforcing.
